internal/pkg/onuadaptercore/omci_onu_upgrade.go

/*
 * Copyright 2020-present Open Networking Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

//Package adaptercoreonu provides the utility for onu devices, flows and statistics
package adaptercoreonu

import (
	"context"
	"encoding/binary"
	"fmt"
	"strconv"
	"sync"
	"time"

	"github.com/boguslaw-wojcik/crc32a"
	"github.com/looplab/fsm"
	"github.com/opencord/omci-lib-go"
	me "github.com/opencord/omci-lib-go/generated"
	"github.com/opencord/voltha-lib-go/v5/pkg/log"
	"github.com/opencord/voltha-protos/v4/go/voltha"
)

const cMaxUint32 = ^uint32(0)

const (
	// internal predefined values - some off them should later be configurable (perhaps with theses as defaults)
	cOmciDownloadSectionSize     = 31 //in bytes
	cOmciDownloadWindowSizeLimit = 31 //in sections for window offset (windowSize(32)-1)
	//cOmciDownloadWindowRetryMax  = 2    // max attempts for a specific window
	cOmciSectionInterleaveMilliseconds = 0  //DownloadSection interleave time in milliseconds (0 for no delay)
	cOmciEndSwDlDelaySeconds           = 1  //End Software Download delay after last section (may be also configurable?)
	cWaitCountEndSwDl                  = 6  //maximum number of EndSwDl requests
	cWaitDelayEndSwDlSeconds           = 10 //duration, how long is waited before next request on EndSwDl
	//cOmciDownloadCompleteTimeout = 5400 //in s for the complete timeout (may be better scale to image size/ noOfWindows)
)

const (
	// events of config PON ANI port FSM
	upgradeEvStart              = "upgradeEvStart"
	upgradeEvAdapterDownload    = "upgradeEvAdapterDownload"
	upgradeEvPrepareSwDownload  = "upgradeEvPrepareSwDownload"
	upgradeEvRxStartSwDownload  = "upgradeEvRxStartSwDownload"
	upgradeEvWaitWindowAck      = "upgradeEvWaitWindowAck"
	upgradeEvContinueNextWindow = "upgradeEvContinueNextWindow"
	upgradeEvEndSwDownload      = "upgradeEvEndSwDownload"
	upgradeEvWaitEndDownload    = "upgradeEvWaitEndDownload"
	upgradeEvContinueFinalize   = "upgradeEvContinueFinalize"
	upgradeEvCheckImageName     = "upgradeEvCheckImageName"
	upgradeEvWaitForActivate    = "upgradeEvWaitForActivate"
	upgradeEvRequestActivate    = "upgradeEvRequestActivate"
	upgradeEvActivationDone     = "upgradeEvActivationDone"
	upgradeEvWaitForCommit      = "upgradeEvWaitForCommit"
	upgradeEvCommitSw           = "upgradeEvCommitSw"
	upgradeEvCheckCommitted     = "upgradeEvCheckCommitted"

	//upgradeEvTimeoutSimple  = "upgradeEvTimeoutSimple"
	//upgradeEvTimeoutMids    = "upgradeEvTimeoutMids"
	upgradeEvReset   = "upgradeEvReset"
	upgradeEvAbort   = "upgradeEvAbort"
	upgradeEvRestart = "upgradeEvRestart"
)

const (
	// states of config PON ANI port FSM
	upgradeStDisabled           = "upgradeStDisabled"
	upgradeStStarting           = "upgradeStStarting"
	upgradeStWaitingAdapterDL   = "upgradeStWaitingAdapterDL"
	upgradeStPreparingDL        = "upgradeStPreparingDL"
	upgradeStDLSection          = "upgradeStDLSection"
	upgradeStVerifyWindow       = "upgradeStVerifyWindow"
	upgradeStFinalizeDL         = "upgradeStFinalizeDL"
	upgradeStWaitEndDL          = "upgradeStWaitEndDL"
	upgradeStCheckImageName     = "upgradeStCheckImageName"
	upgradeStWaitForActivate    = "upgradeStWaitForActivate"
	upgradeStRequestingActivate = "upgradeStRequestingActivate"
	upgradeStActivated          = "upgradeStActivated"
	upgradeStWaitForCommit      = "upgradeStWaitForCommit"
	upgradeStCommitSw           = "upgradeStCommitSw"
	upgradeStCheckCommitted     = "upgradeStCheckCommitted"
	upgradeStResetting          = "upgradeStResetting"
)

//required definition for IdleState detection for activities on OMCI
const cOnuUpgradeFsmIdleState = upgradeStWaitForCommit

//OnuUpgradeFsm defines the structure for the state machine to config the PON ANI ports of ONU UNI ports via OMCI
type OnuUpgradeFsm struct {
	pDeviceHandler   *deviceHandler
	pDownloadManager *adapterDownloadManager
	pFileManager     *fileDownloadManager //used from R2.8 with new API version
	deviceID         string
	pDevEntry        *OnuDeviceEntry
	pOmciCC          *omciCC
	pOnuDB           *onuDeviceDB
	requestEvent     OnuDeviceEvent
	//omciMIdsResponseReceived chan bool //seperate channel needed for checking multiInstance OMCI message responses
	pAdaptFsm                        *AdapterFsm
	pImageDsc                        *voltha.ImageDownload
	imageBuffer                      []byte
	origImageLength                  uint32        //as also limited by OMCI
	imageCRC                         uint32        //as per OMCI - ITU I.363.5 crc
	imageLength                      uint32        //including last bytes padding
	omciDownloadWindowSizeLimit      uint8         //windowSize-1 in sections
	omciDownloadWindowSizeLast       uint8         //number of sections in last window
	noOfSections                     uint32        //uint32 range for sections should be sufficient for very long images
	nextDownloadSectionsAbsolute     uint32        //number of next section to download in overall image
	nextDownloadSectionsWindow       uint8         //number of next section to download within current window
	noOfWindows                      uint32        //uint32 range for windows should be sufficient for very long images
	nextDownloadWindow               uint32        //number of next window to download
	inactiveImageMeID                uint16        //ME-ID of the inactive image
	downloadToOnuTimeout4MB          time.Duration //timeout for downloading the image to the ONU for a 4MB image slice
	omciSectionInterleaveDelay       time.Duration //DownloadSectionInterleave delay in milliseconds
	delayEndSwDl                     bool          //flag to provide a delay between last section and EndSwDl
	pLastTxMeInstance                *me.ManagedEntity
	waitCountEndSwDl                 uint8         //number, how often is waited for EndSwDl at maximum
	waitDelayEndSwDl                 time.Duration //duration, how long is waited before next request on EndSwDl
	chReceiveExpectedResponse        chan bool
	useAPIVersion43                  bool         //flag for indication on which API version is used (and accordingly which specific methods)
	mutexUpgradeParams               sync.RWMutex //mutex to protect members for parallel function requests and omci response processing
	imageVersion                     string       //name of the image as used within OMCI (and on extrenal API interface)
	imageIdentifier                  string       //name of the image as used in the adapter
	mutexIsAwaitingAdapterDlResponse sync.RWMutex
	chAdapterDlReady                 chan bool
	isWaitingForAdapterDlResponse    bool
	mutexIsAwaitingOnuDlResponse     sync.RWMutex
	chOnuDlReady                     chan bool
	isWaitingForOnuDlResponse        bool
	activateImage                    bool
	commitImage                      bool
	mutexAbortRequest                sync.RWMutex
	abortRequested                   voltha.ImageState_ImageFailureReason
	conditionalCancelRequested       bool
	volthaDownloadState              voltha.ImageState_ImageDownloadState
	volthaDownloadReason             voltha.ImageState_ImageFailureReason
	volthaImageState                 voltha.ImageState_ImageActivationState
}

//NewOnuUpgradeFsm is the 'constructor' for the state machine to config the PON ANI ports
//  of ONU UNI ports via OMCI
func NewOnuUpgradeFsm(ctx context.Context, apDeviceHandler *deviceHandler,
	apDevEntry *OnuDeviceEntry, apOnuDB *onuDeviceDB,
	aRequestEvent OnuDeviceEvent, aName string, aCommChannel chan Message) *OnuUpgradeFsm {
	instFsm := &OnuUpgradeFsm{
		pDeviceHandler:              apDeviceHandler,
		deviceID:                    apDeviceHandler.deviceID,
		pDevEntry:                   apDevEntry,
		pOmciCC:                     apDevEntry.PDevOmciCC,
		pOnuDB:                      apOnuDB,
		requestEvent:                aRequestEvent,
		omciDownloadWindowSizeLimit: cOmciDownloadWindowSizeLimit,
		omciSectionInterleaveDelay:  cOmciSectionInterleaveMilliseconds,
		downloadToOnuTimeout4MB:     apDeviceHandler.pOpenOnuAc.dlToOnuTimeout4M,
		waitCountEndSwDl:            cWaitCountEndSwDl,
		waitDelayEndSwDl:            cWaitDelayEndSwDlSeconds,
		volthaDownloadState:         voltha.ImageState_DOWNLOAD_STARTED, //if FSM created we can assume that the download (to adapter) really started
		volthaDownloadReason:        voltha.ImageState_NO_ERROR,
		volthaImageState:            voltha.ImageState_IMAGE_UNKNOWN,
		abortRequested:              voltha.ImageState_NO_ERROR,
	}
	instFsm.chReceiveExpectedResponse = make(chan bool)
	instFsm.chAdapterDlReady = make(chan bool)
	instFsm.chOnuDlReady = make(chan bool)

	instFsm.pAdaptFsm = NewAdapterFsm(aName, instFsm.deviceID, aCommChannel)
	if instFsm.pAdaptFsm == nil {
		logger.Errorw(ctx, "OnuUpgradeFsm's AdapterFsm could not be instantiated!!", log.Fields{
			"device-id": instFsm.deviceID})
		return nil
	}
	instFsm.pAdaptFsm.pFsm = fsm.NewFSM(
		upgradeStDisabled,
		fsm.Events{
			{Name: upgradeEvStart, Src: []string{upgradeStDisabled}, Dst: upgradeStStarting},
			{Name: upgradeEvAdapterDownload, Src: []string{upgradeStStarting}, Dst: upgradeStWaitingAdapterDL},
			{Name: upgradeEvPrepareSwDownload, Src: []string{upgradeStStarting, upgradeStWaitingAdapterDL}, Dst: upgradeStPreparingDL},
			{Name: upgradeEvRxStartSwDownload, Src: []string{upgradeStPreparingDL}, Dst: upgradeStDLSection},
			{Name: upgradeEvWaitWindowAck, Src: []string{upgradeStDLSection}, Dst: upgradeStVerifyWindow},
			{Name: upgradeEvContinueNextWindow, Src: []string{upgradeStVerifyWindow}, Dst: upgradeStDLSection},
			{Name: upgradeEvEndSwDownload, Src: []string{upgradeStVerifyWindow}, Dst: upgradeStFinalizeDL},
			{Name: upgradeEvWaitEndDownload, Src: []string{upgradeStFinalizeDL}, Dst: upgradeStWaitEndDL},
			{Name: upgradeEvContinueFinalize, Src: []string{upgradeStWaitEndDL}, Dst: upgradeStFinalizeDL},
			//upgradeStCheckImageName only used with useAPIVersion43
			{Name: upgradeEvCheckImageName, Src: []string{upgradeStWaitEndDL}, Dst: upgradeStCheckImageName},
			//upgradeEvWaitForActivate state transitions depend on useAPIVersion43
			{Name: upgradeEvWaitForActivate, Src: []string{upgradeStWaitEndDL, upgradeStCheckImageName}, Dst: upgradeStWaitForActivate},
			//upgradeEvRequestActivate state transitions depend on useAPIVersion43
			{Name: upgradeEvRequestActivate, Src: []string{upgradeStStarting, upgradeStWaitEndDL, upgradeStCheckImageName,
				upgradeStWaitForActivate}, Dst: upgradeStRequestingActivate}, //allows also for direct activation (without download) [TODO!!!]
			{Name: upgradeEvActivationDone, Src: []string{upgradeStRequestingActivate}, Dst: upgradeStActivated},
			{Name: upgradeEvWaitForCommit, Src: []string{upgradeStRequestingActivate}, Dst: upgradeStWaitForCommit},
			{Name: upgradeEvCommitSw, Src: []string{upgradeStStarting, upgradeStRequestingActivate, upgradeStWaitForCommit,
				upgradeStActivated}, Dst: upgradeStCommitSw}, //allows also for direct commitment (without download) [TODO!!!]
			{Name: upgradeEvCheckCommitted, Src: []string{upgradeStCommitSw}, Dst: upgradeStCheckCommitted},

			/*
				{Name: upgradeEvTimeoutSimple, Src: []string{
					upgradeStCreatingDot1PMapper, upgradeStCreatingMBPCD, upgradeStSettingTconts, upgradeStSettingDot1PMapper}, Dst: upgradeStStarting},
				{Name: upgradeEvTimeoutMids, Src: []string{
					upgradeStCreatingGemNCTPs, upgradeStCreatingGemIWs, upgradeStSettingPQs}, Dst: upgradeStStarting},
			*/
			// exceptional treatments
			//on upgradeEvReset: upgradeStRequestingActivate, upgradeStWaitForCommit and upgradeStActivated are not reset
			// (to let the FSM survive the expected OnuDown indication)
			{Name: upgradeEvReset, Src: []string{upgradeStStarting, upgradeStWaitingAdapterDL, upgradeStPreparingDL, upgradeStDLSection,
				upgradeStVerifyWindow, upgradeStDLSection, upgradeStFinalizeDL, upgradeStWaitEndDL, upgradeStCheckImageName,
				upgradeStWaitForActivate,
				upgradeStCommitSw, upgradeStCheckCommitted},
				Dst: upgradeStResetting},
			{Name: upgradeEvAbort, Src: []string{upgradeStStarting, upgradeStWaitingAdapterDL, upgradeStPreparingDL, upgradeStDLSection,
				upgradeStVerifyWindow, upgradeStDLSection, upgradeStFinalizeDL, upgradeStWaitEndDL, upgradeStCheckImageName,
				upgradeStWaitForActivate,
				upgradeStRequestingActivate, upgradeStActivated, upgradeStWaitForCommit,
				upgradeStCommitSw, upgradeStCheckCommitted},
				Dst: upgradeStResetting},
			{Name: upgradeEvRestart, Src: []string{upgradeStResetting}, Dst: upgradeStDisabled},
		},
		fsm.Callbacks{
			"enter_state":                          func(e *fsm.Event) { instFsm.pAdaptFsm.logFsmStateChange(ctx, e) },
			"enter_" + upgradeStStarting:           func(e *fsm.Event) { instFsm.enterStarting(ctx, e) },
			"enter_" + upgradeStWaitingAdapterDL:   func(e *fsm.Event) { instFsm.enterWaitingAdapterDL(ctx, e) },
			"enter_" + upgradeStPreparingDL:        func(e *fsm.Event) { instFsm.enterPreparingDL(ctx, e) },
			"enter_" + upgradeStDLSection:          func(e *fsm.Event) { instFsm.enterDownloadSection(ctx, e) },
			"enter_" + upgradeStVerifyWindow:       func(e *fsm.Event) { instFsm.enterVerifyWindow(ctx, e) },
			"enter_" + upgradeStFinalizeDL:         func(e *fsm.Event) { instFsm.enterFinalizeDL(ctx, e) },
			"enter_" + upgradeStWaitEndDL:          func(e *fsm.Event) { instFsm.enterWaitEndDL(ctx, e) },
			"enter_" + upgradeStCheckImageName:     func(e *fsm.Event) { instFsm.enterCheckImageName(ctx, e) },
			"enter_" + upgradeStRequestingActivate: func(e *fsm.Event) { instFsm.enterActivateSw(ctx, e) },
			"enter_" + upgradeStCommitSw:           func(e *fsm.Event) { instFsm.enterCommitSw(ctx, e) },
			"enter_" + upgradeStCheckCommitted:     func(e *fsm.Event) { instFsm.enterCheckCommitted(ctx, e) },
			"enter_" + upgradeStResetting:          func(e *fsm.Event) { instFsm.enterResetting(ctx, e) },
			"enter_" + upgradeStDisabled:           func(e *fsm.Event) { instFsm.enterDisabled(ctx, e) },
		},
	)
	if instFsm.pAdaptFsm.pFsm == nil {
		logger.Errorw(ctx, "OnuUpgradeFsm's Base FSM could not be instantiated!!", log.Fields{
			"device-id": instFsm.deviceID})
		return nil
	}

	logger.Debugw(ctx, "OnuUpgradeFsm created", log.Fields{"device-id": instFsm.deviceID})
	return instFsm
}

//SetDownloadParams configures the needed parameters for a specific download to the ONU
//  called from 'old' API Activate_image_update()
func (oFsm *OnuUpgradeFsm) SetDownloadParams(ctx context.Context, aInactiveImageID uint16,
	apImageDsc *voltha.ImageDownload, apDownloadManager *adapterDownloadManager) error {
	pBaseFsm := oFsm.pAdaptFsm.pFsm
	if pBaseFsm != nil && pBaseFsm.Is(upgradeStStarting) {
		oFsm.mutexUpgradeParams.Lock()
		logger.Debugw(ctx, "OnuUpgradeFsm Parameter setting", log.Fields{
			"device-id": oFsm.deviceID, "image-description": apImageDsc})
		oFsm.inactiveImageMeID = aInactiveImageID //upgrade state machines run on configured inactive ImageId
		oFsm.pImageDsc = apImageDsc
		oFsm.pDownloadManager = apDownloadManager
		oFsm.activateImage = true
		oFsm.commitImage = true
		oFsm.mutexUpgradeParams.Unlock()

		go func(aPBaseFsm *fsm.FSM) {
			// let the upgrade FSM proceed to PreparingDL
			_ = aPBaseFsm.Event(upgradeEvPrepareSwDownload)
		}(pBaseFsm)
		return nil
	}
	logger.Errorw(ctx, "OnuUpgradeFsm abort: invalid FSM base pointer or state", log.Fields{
		"device-id": oFsm.deviceID})
	return fmt.Errorf(fmt.Sprintf("OnuUpgradeFsm abort: invalid FSM base pointer or state for device-id: %s", oFsm.deviceID))
}

//SetDownloadParamsAfterDownload configures the needed parameters for a specific download to the ONU according to
//  updated API interface with R2.8: start download to ONU if the image is downloaded to the adapter
//  called from 'new' API Download_onu_image
func (oFsm *OnuUpgradeFsm) SetDownloadParamsAfterDownload(ctx context.Context, aInactiveImageID uint16,
	apImageRequest *voltha.DeviceImageDownloadRequest, apDownloadManager *fileDownloadManager,
	aImageIdentifier string) error {
	oFsm.mutexUpgradeParams.Lock()
	var pBaseFsm *fsm.FSM = nil
	if oFsm.pAdaptFsm != nil {
		pBaseFsm = oFsm.pAdaptFsm.pFsm
	}
	if pBaseFsm != nil && pBaseFsm.Is(upgradeStStarting) {
		logger.Debugw(ctx, "OnuUpgradeFsm Parameter setting", log.Fields{
			"device-id": oFsm.deviceID, "image-description": apImageRequest})
		oFsm.useAPIVersion43 = true
		oFsm.inactiveImageMeID = aInactiveImageID //upgrade state machines run on configured inactive ImageId
		oFsm.pFileManager = apDownloadManager
		oFsm.imageIdentifier = aImageIdentifier
		oFsm.imageVersion = apImageRequest.Image.Version
		oFsm.activateImage = apImageRequest.ActivateOnSuccess
		oFsm.commitImage = apImageRequest.CommitOnSuccess
		//TODO: currently straightforward options activate and commit are expected to be set and (unconditionally) done
		//  for separate handling of these options the FSM must accordingly branch from the concerned states - later
		oFsm.mutexUpgradeParams.Unlock()
		_ = pBaseFsm.Event(upgradeEvAdapterDownload) //no need to call the FSM event in background here
		return nil
	}
	oFsm.mutexUpgradeParams.Unlock()
	logger.Errorw(ctx, "OnuUpgradeFsm abort: invalid FSM base pointer or state", log.Fields{
		"device-id": oFsm.deviceID})
	return fmt.Errorf(fmt.Sprintf("OnuUpgradeFsm abort: invalid FSM base pointer or state for device-id: %s", oFsm.deviceID))
}

//SetActivationParamsRunning sets the activate and commit flags for a running download to the ONU according to adapters rpc call
//  called from 'new' API Activate_onu_image
func (oFsm *OnuUpgradeFsm) SetActivationParamsRunning(ctx context.Context,
	aImageIdentifier string, aCommit bool) error {
	oFsm.mutexUpgradeParams.Lock()
	//set activate/commit independent from state, if FSM is already beyond concerned states, then it does not matter anyway
	//  (as long as the Imageidentifier is correct)
	logger.Debugw(ctx, "OnuUpgradeFsm activate/commit parameter setting", log.Fields{
		"device-id": oFsm.deviceID, "image-id": aImageIdentifier, "commit": aCommit})
	if aImageIdentifier != oFsm.imageIdentifier {
		logger.Errorw(ctx, "OnuUpgradeFsm abort: mismatching upgrade image", log.Fields{
			"device-id": oFsm.deviceID, "request-image": aImageIdentifier, "fsm-image": oFsm.imageIdentifier})
		oFsm.mutexUpgradeParams.Unlock()
		return fmt.Errorf(fmt.Sprintf("OnuUpgradeFsm params ignored: requested image-name not used in current upgrade for device-id: %s",
			oFsm.deviceID))
	}
	oFsm.activateImage = true
	oFsm.commitImage = aCommit
	var pBaseFsm *fsm.FSM = nil
	if oFsm.pAdaptFsm != nil {
		pBaseFsm = oFsm.pAdaptFsm.pFsm
	}
	if pBaseFsm != nil {
		if pBaseFsm.Is(upgradeStWaitForActivate) {
			oFsm.volthaDownloadState = voltha.ImageState_DOWNLOAD_STARTED //better choice would be 'UpgradeState=Started'
			oFsm.mutexUpgradeParams.Unlock()
			logger.Debugw(ctx, "OnuUpgradeFsm finish waiting for activate", log.Fields{"device-id": oFsm.deviceID})
			_ = pBaseFsm.Event(upgradeEvRequestActivate) //no need to call the FSM event in background here
		} else {
			oFsm.mutexUpgradeParams.Unlock()
			logger.Debugw(ctx, "OnuUpgradeFsm not (yet?) waiting for activate", log.Fields{
				"device-id": oFsm.deviceID, "current FsmState": pBaseFsm.Current()})
		}
		return nil
	}
	logger.Errorw(ctx, "OnuUpgradeFsm abort: invalid FSM base pointer", log.Fields{
		"device-id": oFsm.deviceID})
	return fmt.Errorf(fmt.Sprintf("OnuUpgradeFsm abort: invalid FSM base pointer for device-id: %s", oFsm.deviceID))
}

//SetActivationParamsStart starts upgrade processing with immediate activation
//  called from 'new' API Activate_onu_image
func (oFsm *OnuUpgradeFsm) SetActivationParamsStart(ctx context.Context, aImageVersion string, aInactiveImageID uint16, aCommit bool) error {
	oFsm.mutexUpgradeParams.Lock()
	var pBaseFsm *fsm.FSM = nil
	if oFsm.pAdaptFsm != nil {
		pBaseFsm = oFsm.pAdaptFsm.pFsm
	}
	if pBaseFsm != nil && pBaseFsm.Is(upgradeStStarting) {
		logger.Debugw(ctx, "OnuUpgradeFsm Parameter setting to start with activation", log.Fields{
			"device-id": oFsm.deviceID, "image-version": aImageVersion})
		oFsm.useAPIVersion43 = true
		oFsm.inactiveImageMeID = aInactiveImageID //upgrade state machines run on configured inactive ImageId
		oFsm.imageVersion = aImageVersion
		oFsm.activateImage = true
		oFsm.commitImage = aCommit
		// indicate start of the upgrade activity
		oFsm.volthaDownloadState = voltha.ImageState_DOWNLOAD_STARTED //better choice would be 'UpgradeState=Started'
		oFsm.volthaImageState = voltha.ImageState_IMAGE_INACTIVE      //as simply applied for inactive image
		oFsm.mutexUpgradeParams.Unlock()
		//directly request the FSM to activate the image
		_ = pBaseFsm.Event(upgradeEvRequestActivate) //no need to call the FSM event in background here
		return nil
	}
	oFsm.mutexUpgradeParams.Unlock()
	logger.Errorw(ctx, "OnuUpgradeFsm abort: invalid FSM base pointer or state", log.Fields{
		"device-id": oFsm.deviceID})
	return fmt.Errorf(fmt.Sprintf("OnuUpgradeFsm abort: invalid FSM base pointer or state for device-id: %s", oFsm.deviceID))
}

//SetCommitmentParamsRunning sets the commit flag for a running download to the ONU according to adapters rpc call
//  called from 'new' API Commit_onu_image
func (oFsm *OnuUpgradeFsm) SetCommitmentParamsRunning(ctx context.Context,
	aImageIdentifier string, aImageVersion string) error {
	oFsm.mutexUpgradeParams.Lock()
	//set commit independent from state, if FSM is already beyond commit state (just ready), then it does not matter anyway
	//  (as long as the Imageidentifier is correct)
	logger.Debugw(ctx, "OnuUpgradeFsm commit parameter setting", log.Fields{
		"device-id": oFsm.deviceID, "image-id": aImageIdentifier})
	if (aImageIdentifier != oFsm.imageIdentifier) && (aImageVersion != oFsm.imageVersion) {
		logger.Errorw(ctx, "OnuUpgradeFsm abort: mismatching upgrade image", log.Fields{
			"device-id": oFsm.deviceID, "request-identifier": aImageIdentifier, "fsm-identifier": oFsm.imageIdentifier,
			"request-version": aImageVersion, "fsm-version": oFsm.imageVersion})
		oFsm.mutexUpgradeParams.Unlock()
		return fmt.Errorf(fmt.Sprintf("OnuUpgradeFsm params ignored: requested image-name not used in current upgrade for device-id: %s",
			oFsm.deviceID))
	}
	oFsm.commitImage = true
	oFsm.volthaDownloadState = voltha.ImageState_DOWNLOAD_STARTED //better choice would be 'UpgradeState=Started'
	oFsm.mutexUpgradeParams.Unlock()
	var pBaseFsm *fsm.FSM = nil
	if oFsm.pAdaptFsm != nil {
		pBaseFsm = oFsm.pAdaptFsm.pFsm
	}
	if pBaseFsm != nil {
		//let the FSM decide if it is ready to process the event
		logger.Debugw(ctx, "OnuUpgradeFsm requesting commit",
			log.Fields{"device-id": oFsm.deviceID, "current FsmState": pBaseFsm.Current()})
		_ = pBaseFsm.Event(upgradeEvCommitSw) //no need to call the FSM event in background here
		return nil
	}
	//should never occur
	logger.Errorw(ctx, "OnuUpgradeFsm abort: invalid FSM base pointer", log.Fields{
		"device-id": oFsm.deviceID})
	return fmt.Errorf(fmt.Sprintf("OnuUpgradeFsm abort: invalid FSM base pointer for device-id: %s", oFsm.deviceID))
}

//SetCommitmentParamsStart starts upgrade processing with immediate commitment
//  called from 'new' API Commit_onu_image
func (oFsm *OnuUpgradeFsm) SetCommitmentParamsStart(ctx context.Context, aImageVersion string, aActiveImageID uint16) error {
	oFsm.mutexUpgradeParams.Lock()
	var pBaseFsm *fsm.FSM = nil
	if oFsm.pAdaptFsm != nil {
		pBaseFsm = oFsm.pAdaptFsm.pFsm
	}
	if pBaseFsm != nil && pBaseFsm.Is(upgradeStStarting) {
		logger.Debugw(ctx, "OnuUpgradeFsm Parameter setting to start with commitment", log.Fields{
			"device-id": oFsm.deviceID, "image-version": aImageVersion})
		oFsm.useAPIVersion43 = true
		oFsm.inactiveImageMeID = aActiveImageID //upgrade state machines inactive ImageId is the new active ImageId
		oFsm.imageVersion = aImageVersion
		oFsm.commitImage = true
		oFsm.volthaDownloadState = voltha.ImageState_DOWNLOAD_STARTED //better choice would be 'UpgradeState=Started'
		oFsm.volthaImageState = voltha.ImageState_IMAGE_ACTIVE        //as simply applied for active image
		oFsm.mutexUpgradeParams.Unlock()
		//directly request the FSM to commit the image
		_ = pBaseFsm.Event(upgradeEvCommitSw) //no need to call the FSM event in background here
		return nil
	}
	oFsm.mutexUpgradeParams.Unlock()
	logger.Errorw(ctx, "OnuUpgradeFsm abort: invalid FSM base pointer or state", log.Fields{
		"device-id": oFsm.deviceID})
	return fmt.Errorf(fmt.Sprintf("OnuUpgradeFsm abort: invalid FSM base pointer or state for device-id: %s", oFsm.deviceID))
}

//GetCommitFlag delivers the commit flag that was configured here
func (oFsm *OnuUpgradeFsm) GetCommitFlag(ctx context.Context) bool {
	oFsm.mutexUpgradeParams.RLock()
	defer oFsm.mutexUpgradeParams.RUnlock()
	return oFsm.commitImage
}

//GetImageStates delivers the download/image states as per device proto buf definition
func (oFsm *OnuUpgradeFsm) GetImageStates(ctx context.Context,
	aImageIdentifier string, aVersion string) *voltha.ImageState {
	pImageState := &voltha.ImageState{}
	pImageState.Version = aVersion //version as requested
	// check if the request refers to some active image/version of the processing
	oFsm.mutexUpgradeParams.RLock()
	if (aImageIdentifier == oFsm.imageIdentifier) || (aVersion == oFsm.imageVersion) {
		pImageState.DownloadState = oFsm.volthaDownloadState
		pImageState.Reason = oFsm.volthaDownloadReason
		pImageState.ImageState = oFsm.volthaImageState
	} else {
		pImageState.DownloadState = voltha.ImageState_DOWNLOAD_UNKNOWN
		pImageState.Reason = voltha.ImageState_NO_ERROR
		pImageState.ImageState = voltha.ImageState_IMAGE_UNKNOWN
	}
	oFsm.mutexUpgradeParams.RUnlock()
	return pImageState
}

//GetSpecificImageState delivers ImageState of the download/image states as per device proto buf definition
func (oFsm *OnuUpgradeFsm) GetSpecificImageState(ctx context.Context) voltha.ImageState_ImageActivationState {
	oFsm.mutexUpgradeParams.RLock()
	imageState := oFsm.volthaImageState
	oFsm.mutexUpgradeParams.RUnlock()
	return imageState
}

//SetImageStateActive sets the FSM internal volthaImageState to ImageState_IMAGE_ACTIVE
func (oFsm *OnuUpgradeFsm) SetImageStateActive(ctx context.Context) {
	oFsm.mutexUpgradeParams.Lock()
	defer oFsm.mutexUpgradeParams.Unlock()
	oFsm.volthaImageState = voltha.ImageState_IMAGE_ACTIVE
	if !oFsm.commitImage {
		//if commit is not additionally set, regard the upgrade activity as successful
		oFsm.volthaDownloadState = voltha.ImageState_DOWNLOAD_SUCCEEDED //better choice would be 'UpgradeState=Succeeded'
	}
}

//GetImageVersion delivers image-version of the running upgrade
func (oFsm *OnuUpgradeFsm) GetImageVersion(ctx context.Context) string {
	oFsm.mutexUpgradeParams.RLock()
	imageVersion := oFsm.imageVersion
	oFsm.mutexUpgradeParams.RUnlock()
	return imageVersion
}

//CancelProcessing ensures that suspended processing at waiting on some response is aborted and reset of FSM
func (oFsm *OnuUpgradeFsm) CancelProcessing(ctx context.Context, abCompleteAbort bool,
	aReason voltha.ImageState_ImageFailureReason) {
	oFsm.mutexAbortRequest.Lock()
	oFsm.abortRequested = aReason //possibly abort the sectionDownload loop
	oFsm.mutexAbortRequest.Unlock()
	//mutex protection is required for possible concurrent access to FSM members
	//attention: for an unbuffered channel the sender is blocked until the value is received (processed)!
	// accordingly the mutex must be released before sending to channel here (mutex acquired in receiver)
	oFsm.mutexIsAwaitingAdapterDlResponse.RLock()
	if oFsm.isWaitingForAdapterDlResponse {
		oFsm.mutexIsAwaitingAdapterDlResponse.RUnlock()
		//use channel to indicate that the download response waiting shall be aborted for this device (channel)
		oFsm.chAdapterDlReady <- false
	} else {
		oFsm.mutexIsAwaitingAdapterDlResponse.RUnlock()
	}
	//chOnuDlReady is cleared as part of the FSM reset processing (from enterResetting())

	// in any case (even if it might be automatically requested by above cancellation of waiting) ensure resetting the FSM
	// specific here: See definition of state changes: some states are excluded from reset for possible later commit
	pAdaptFsm := oFsm.pAdaptFsm
	if pAdaptFsm != nil {
		// calling FSM events in background to avoid blocking of the caller
		go func(aPAFsm *AdapterFsm) {
			if aPAFsm.pFsm != nil {
				if aPAFsm.pFsm.Is(upgradeStWaitEndDL) {
					oFsm.chReceiveExpectedResponse <- false //which aborts the FSM in WaitEndDL state
				}
				// in case of state-conditional request the

				var err error
				if abCompleteAbort {
					oFsm.mutexUpgradeParams.Lock()
					//any previous lingering conditional cancelRequest is superseded by this abortion
					oFsm.conditionalCancelRequested = false
					if aReason == voltha.ImageState_CANCELLED_ON_REQUEST {
						oFsm.volthaDownloadState = voltha.ImageState_DOWNLOAD_CANCELLED
					} else {
						oFsm.volthaDownloadState = voltha.ImageState_DOWNLOAD_FAILED
					}
					oFsm.volthaDownloadReason = aReason
					oFsm.mutexUpgradeParams.Unlock()
					err = aPAFsm.pFsm.Event(upgradeEvAbort) //as unconditional default FSM cancellation
				} else {
					//at conditional request the image states are set when reaching the reset state
					oFsm.conditionalCancelRequested = true
					err = aPAFsm.pFsm.Event(upgradeEvReset) //as state-conditional default FSM cleanup
				}
				if err != nil {
					//error return is expected in case of conditional request and no state transition
					logger.Debugw(ctx, "onu upgrade fsm could not cancel with abort/reset event", log.Fields{
						"device-id": oFsm.deviceID, "error": err})
				}
			} //else the FSM seems already to be in some released state
		}(pAdaptFsm)
	}
}

func (oFsm *OnuUpgradeFsm) enterStarting(ctx context.Context, e *fsm.Event) {
	logger.Debugw(ctx, "OnuUpgradeFsm start", log.Fields{"in state": e.FSM.Current(),
		"device-id": oFsm.deviceID})

	// start go routine for processing of LockState messages
	go oFsm.processOmciUpgradeMessages(ctx)
}

//enterWaitingAdapterDL state can only be reached with useAPIVersion43
func (oFsm *OnuUpgradeFsm) enterWaitingAdapterDL(ctx context.Context, e *fsm.Event) {
	logger.Debugw(ctx, "OnuUpgradeFsm waiting for adapter download", log.Fields{"in state": e.FSM.Current(),
		"device-id": oFsm.deviceID})
	syncChannel := make(chan struct{})
	go oFsm.waitOnDownloadToAdapterReady(ctx, syncChannel, oFsm.chAdapterDlReady)
	//block until the wait routine is really blocked on chAdapterDlReady
	<-syncChannel
	go oFsm.pFileManager.RequestDownloadReady(ctx, oFsm.imageIdentifier, oFsm.chAdapterDlReady)
}

func (oFsm *OnuUpgradeFsm) enterPreparingDL(ctx context.Context, e *fsm.Event) {
	logger.Debugw(ctx, "OnuUpgradeFsm prepare Download to Onu", log.Fields{"in state": e.FSM.Current(),
		"device-id": oFsm.deviceID})

	var fileLen int64
	var err error
	oFsm.mutexUpgradeParams.Lock()
	if oFsm.useAPIVersion43 {
		//with the new API structure download to adapter is implicit and we have to wait until the image is available
		fileLen, err = oFsm.pFileManager.GetImageBufferLen(ctx, oFsm.imageIdentifier)
	} else {
		fileLen, err = oFsm.pDownloadManager.getImageBufferLen(ctx, oFsm.pImageDsc.Name, oFsm.pImageDsc.LocalDir)
	}
	if err != nil || fileLen > int64(cMaxUint32) {
		oFsm.volthaDownloadState = voltha.ImageState_DOWNLOAD_FAILED
		oFsm.volthaDownloadReason = voltha.ImageState_UNKNOWN_ERROR //Something like 'LOCAL_FILE_ERROR' would be better (proto)
		oFsm.volthaImageState = voltha.ImageState_IMAGE_UNKNOWN
		oFsm.mutexUpgradeParams.Unlock()
		logger.Errorw(ctx, "OnuUpgradeFsm abort: problems getting image buffer length", log.Fields{
			"device-id": oFsm.deviceID, "error": err, "length": fileLen})
		pBaseFsm := oFsm.pAdaptFsm
		// Can't call FSM Event directly, decoupling it
		go func(a_pAFsm *AdapterFsm) {
			_ = a_pAFsm.pFsm.Event(upgradeEvAbort)
		}(pBaseFsm)
		return
	}

	//copy file content to buffer
	oFsm.imageBuffer = make([]byte, fileLen)
	if oFsm.useAPIVersion43 {
		oFsm.imageBuffer, err = oFsm.pFileManager.GetDownloadImageBuffer(ctx, oFsm.imageIdentifier)
	} else {
		oFsm.imageBuffer, err = oFsm.pDownloadManager.getDownloadImageBuffer(ctx, oFsm.pImageDsc.Name, oFsm.pImageDsc.LocalDir)
	}
	if err != nil {
		oFsm.volthaDownloadState = voltha.ImageState_DOWNLOAD_FAILED
		oFsm.volthaDownloadReason = voltha.ImageState_UNKNOWN_ERROR //Something like 'LOCAL_FILE_ERROR' would be better (proto)
		oFsm.volthaImageState = voltha.ImageState_IMAGE_UNKNOWN
		oFsm.mutexUpgradeParams.Unlock()
		logger.Errorw(ctx, "OnuUpgradeFsm abort: can't get image buffer", log.Fields{
			"device-id": oFsm.deviceID, "error": err})
		pBaseFsm := oFsm.pAdaptFsm
		// Can't call FSM Event directly, decoupling it
		go func(a_pAFsm *AdapterFsm) {
			_ = a_pAFsm.pFsm.Event(upgradeEvAbort)
		}(pBaseFsm)
		return
	}

	oFsm.noOfSections = uint32(fileLen / cOmciDownloadSectionSize)
	if fileLen%cOmciDownloadSectionSize > 0 {
		bufferPadding := make([]byte, cOmciDownloadSectionSize-uint32((fileLen)%cOmciDownloadSectionSize))
		//expand the imageBuffer to exactly fit multiples of cOmciDownloadSectionSize with padding
		oFsm.imageBuffer = append(oFsm.imageBuffer[:(fileLen)], bufferPadding...)
		oFsm.noOfSections++
	}
	oFsm.origImageLength = uint32(fileLen)
	oFsm.imageLength = uint32(len(oFsm.imageBuffer))
	logger.Infow(ctx, "OnuUpgradeFsm starts with StartSwDl values", log.Fields{
		"MeId": oFsm.inactiveImageMeID, "windowSizeLimit": oFsm.omciDownloadWindowSizeLimit,
		"ImageSize": oFsm.imageLength, "original file size": fileLen})
	//"NumberOfCircuitPacks": oFsm.numberCircuitPacks, "CircuitPacks MeId": 0}) //parallel circuit packs download not supported

	oFsm.mutexUpgradeParams.Unlock()
	go oFsm.waitOnDownloadToOnuReady(ctx, oFsm.chOnuDlReady) // start supervision of the complete download-to-ONU procedure

	err = oFsm.pOmciCC.sendStartSoftwareDownload(log.WithSpanFromContext(context.TODO(), ctx), oFsm.pDeviceHandler.pOpenOnuAc.omciTimeout, false,
		oFsm.pAdaptFsm.commChan, oFsm.inactiveImageMeID, oFsm.omciDownloadWindowSizeLimit, oFsm.origImageLength)
	if err != nil {
		logger.Errorw(ctx, "StartSwDl abort: can't send section", log.Fields{
			"device-id": oFsm.deviceID, "error": err})
		oFsm.abortOnOmciError(ctx, true, voltha.ImageState_IMAGE_UNKNOWN) //no ImageState update
		return
	}
}

func (oFsm *OnuUpgradeFsm) enterDownloadSection(ctx context.Context, e *fsm.Event) {
	logger.Debugw(ctx, "OnuUpgradeFsm start downloading sections", log.Fields{
		"device-id": oFsm.deviceID, "absolute window": oFsm.nextDownloadWindow})

	var windowAckRequest uint8 = 0
	var bufferStartOffset uint32
	var bufferEndOffset uint32
	var downloadSection []byte
	framePrint := false //default no printing of downloadSection frames
	oFsm.mutexUpgradeParams.Lock()
	if oFsm.nextDownloadSectionsAbsolute == 0 {
		//debug print of first section frame
		framePrint = true
		oFsm.volthaImageState = voltha.ImageState_IMAGE_DOWNLOADING
	}

	for {
		oFsm.mutexAbortRequest.RLock()
		// this way out of the section download loop on abort request
		if oFsm.abortRequested != voltha.ImageState_NO_ERROR {
			if oFsm.abortRequested == voltha.ImageState_CANCELLED_ON_REQUEST {
				oFsm.volthaDownloadState = voltha.ImageState_DOWNLOAD_CANCELLED
			} else {
				oFsm.volthaDownloadState = voltha.ImageState_DOWNLOAD_FAILED
			}
			oFsm.volthaDownloadReason = oFsm.abortRequested
			oFsm.mutexAbortRequest.RUnlock()
			oFsm.mutexUpgradeParams.Unlock()
			pBaseFsm := oFsm.pAdaptFsm
			// Can't call FSM Event directly, decoupling it
			go func(a_pAFsm *AdapterFsm) {
				_ = a_pAFsm.pFsm.Event(upgradeEvAbort)
			}(pBaseFsm)
			return
		}
		oFsm.mutexAbortRequest.RUnlock()

		bufferStartOffset = oFsm.nextDownloadSectionsAbsolute * cOmciDownloadSectionSize
		bufferEndOffset = bufferStartOffset + cOmciDownloadSectionSize - 1 //for representing cOmciDownloadSectionSizeLimit values
		logger.Debugw(ctx, "DlSection values are", log.Fields{
			"DlSectionNoAbsolute": oFsm.nextDownloadSectionsAbsolute,
			"DlSectionWindow":     oFsm.nextDownloadSectionsWindow,
			"startOffset":         bufferStartOffset, "endOffset": bufferEndOffset})
		if bufferStartOffset+1 > oFsm.imageLength || bufferEndOffset+1 > oFsm.imageLength { //should never occur in this state
			logger.Errorw(ctx, "OnuUpgradeFsm buffer error: exceeded length", log.Fields{
				"device-id": oFsm.deviceID, "bufferStartOffset": bufferStartOffset,
				"bufferEndOffset": bufferEndOffset, "imageLength": oFsm.imageLength})
			oFsm.volthaDownloadState = voltha.ImageState_DOWNLOAD_FAILED
			oFsm.volthaDownloadReason = voltha.ImageState_UNKNOWN_ERROR //Something like 'LOCAL_FILE_ERROR' would be better (proto)
			oFsm.mutexUpgradeParams.Unlock()
			//logical error -- reset the FSM
			pBaseFsm := oFsm.pAdaptFsm
			// Can't call FSM Event directly, decoupling it
			go func(a_pAFsm *AdapterFsm) {
				_ = a_pAFsm.pFsm.Event(upgradeEvAbort)
			}(pBaseFsm)
			return
		}
		downloadSection = oFsm.imageBuffer[bufferStartOffset : bufferEndOffset+1]
		if oFsm.nextDownloadSectionsWindow == oFsm.omciDownloadWindowSizeLimit {
			windowAckRequest = 1
			logger.Debugw(ctx, "DlSection expect Response for complete window", log.Fields{
				"device-id": oFsm.deviceID, "in window": oFsm.nextDownloadWindow})
		}
		if oFsm.nextDownloadSectionsAbsolute+1 >= oFsm.noOfSections {
			windowAckRequest = 1
			framePrint = true //debug print of last frame
			oFsm.omciDownloadWindowSizeLast = oFsm.nextDownloadSectionsWindow
			logger.Infow(ctx, "DlSection expect Response for last window (section)", log.Fields{
				"device-id": oFsm.deviceID, "DlSectionNoAbsolute": oFsm.nextDownloadSectionsAbsolute})
		}
		oFsm.mutexUpgradeParams.Unlock() //unlock here to give other functions some chance to process during/after the send request
		err := oFsm.pOmciCC.sendDownloadSection(log.WithSpanFromContext(context.TODO(), ctx), oFsm.pDeviceHandler.pOpenOnuAc.omciTimeout, false,
			oFsm.pAdaptFsm.commChan, oFsm.inactiveImageMeID, windowAckRequest, oFsm.nextDownloadSectionsWindow, downloadSection, framePrint)
		if err != nil {
			logger.Errorw(ctx, "DlSection abort: can't send section", log.Fields{
				"device-id": oFsm.deviceID, "section absolute": oFsm.nextDownloadSectionsAbsolute, "error": err})
			oFsm.abortOnOmciError(ctx, true, voltha.ImageState_IMAGE_UNKNOWN) //no ImageState update
			return
		}
		oFsm.mutexUpgradeParams.Lock()
		oFsm.nextDownloadSectionsAbsolute++ //always increase the absolute section counter after having sent one
		if windowAckRequest == 1 {
			pBaseFsm := oFsm.pAdaptFsm
			// Can't call FSM Event directly, decoupling it
			oFsm.mutexUpgradeParams.Unlock()
			go func(a_pAFsm *AdapterFsm) {
				_ = a_pAFsm.pFsm.Event(upgradeEvWaitWindowAck) //state transition to upgradeStVerifyWindow
			}(pBaseFsm)
			return
		}
		framePrint = false                //for the next Section frame (if wanted, can be enabled in logic before sendXXX())
		oFsm.nextDownloadSectionsWindow++ //increase the window related section counter only if not in the last section
		if oFsm.omciSectionInterleaveDelay > 0 {
			//ensure a defined intersection-time-gap to leave space for further processing, other ONU's ...
			oFsm.mutexUpgradeParams.Unlock() //unlock here to give other functions some chance to process during/after the send request
			time.Sleep(oFsm.omciSectionInterleaveDelay * time.Millisecond)
			oFsm.mutexUpgradeParams.Lock()
		}
	}
}

func (oFsm *OnuUpgradeFsm) enterVerifyWindow(ctx context.Context, e *fsm.Event) {
	logger.Debugw(ctx, "OnuUpgradeFsm verify DL window ack", log.Fields{
		"for window": oFsm.nextDownloadWindow, "device-id": oFsm.deviceID})
}

func (oFsm *OnuUpgradeFsm) enterFinalizeDL(ctx context.Context, e *fsm.Event) {
	logger.Infow(ctx, "OnuUpgradeFsm finalize DL", log.Fields{
		"device-id": oFsm.deviceID, "crc": strconv.FormatInt(int64(oFsm.imageCRC), 16), "delay": oFsm.delayEndSwDl})

	oFsm.mutexUpgradeParams.RLock()
	if oFsm.delayEndSwDl {
		oFsm.mutexUpgradeParams.RUnlock()
		//give the ONU some time for image evaluation (hoping it does not base that on first EndSwDl itself)
		// should not be set in case this state is used for real download abort (not yet implemented)
		time.Sleep(cOmciEndSwDlDelaySeconds * time.Second)
	} else {
		oFsm.mutexUpgradeParams.RUnlock()
	}

	pBaseFsm := oFsm.pAdaptFsm
	if pBaseFsm == nil {
		logger.Errorw(ctx, "EndSwDl abort: BaseFsm invalid", log.Fields{"device-id": oFsm.deviceID})
		oFsm.mutexUpgradeParams.Lock()
		oFsm.volthaDownloadState = voltha.ImageState_DOWNLOAD_FAILED
		oFsm.volthaDownloadReason = voltha.ImageState_UNKNOWN_ERROR
		oFsm.mutexUpgradeParams.Unlock()
		// Can't call FSM Event directly, decoupling it
		go func(a_pAFsm *AdapterFsm) {
			_ = a_pAFsm.pFsm.Event(upgradeEvAbort)
		}(pBaseFsm)
		return
	}
	err := oFsm.pOmciCC.sendEndSoftwareDownload(log.WithSpanFromContext(context.TODO(), ctx), oFsm.pDeviceHandler.pOpenOnuAc.omciTimeout, false,
		oFsm.pAdaptFsm.commChan, oFsm.inactiveImageMeID, oFsm.origImageLength, oFsm.imageCRC)
	if err != nil {
		logger.Errorw(ctx, "EndSwDl abort: can't send section", log.Fields{
			"device-id": oFsm.deviceID, "error": err})
		oFsm.abortOnOmciError(ctx, true, voltha.ImageState_IMAGE_UNKNOWN) //no ImageState update
		return
	}
	// go waiting for the EndSwDLResponse and check, if the ONU is ready for activation
	// Can't call FSM Event directly, decoupling it
	go func(a_pAFsm *AdapterFsm) {
		_ = a_pAFsm.pFsm.Event(upgradeEvWaitEndDownload)
	}(pBaseFsm)
}

func (oFsm *OnuUpgradeFsm) enterWaitEndDL(ctx context.Context, e *fsm.Event) {
	logger.Infow(ctx, "OnuUpgradeFsm WaitEndDl", log.Fields{
		"device-id": oFsm.deviceID, "wait delay": oFsm.waitDelayEndSwDl * time.Second, "wait count": oFsm.waitCountEndSwDl})
	if oFsm.waitCountEndSwDl == 0 {
		logger.Errorw(ctx, "WaitEndDl abort: max limit of EndSwDL reached", log.Fields{
			"device-id": oFsm.deviceID})
		pBaseFsm := oFsm.pAdaptFsm
		if pBaseFsm == nil {
			logger.Errorw(ctx, "WaitEndDl abort: BaseFsm invalid", log.Fields{
				"device-id": oFsm.deviceID})
			return
		}
		oFsm.mutexUpgradeParams.Lock()
		oFsm.volthaDownloadState = voltha.ImageState_DOWNLOAD_FAILED
		oFsm.volthaDownloadReason = voltha.ImageState_IMAGE_REFUSED_BY_ONU //Something like 'END_DOWNLOAD_TIMEOUT' would be better (proto)
		oFsm.mutexUpgradeParams.Unlock()
		go func(a_pAFsm *AdapterFsm) {
			_ = a_pAFsm.pFsm.Event(upgradeEvAbort)
		}(pBaseFsm)
		return
	}

	oFsm.waitCountEndSwDl--
	select {
	case <-time.After(oFsm.waitDelayEndSwDl * time.Second):
		pBaseFsm := oFsm.pAdaptFsm
		if pBaseFsm == nil {
			logger.Errorw(ctx, "WaitEndDl abort: BaseFsm invalid", log.Fields{
				"device-id": oFsm.deviceID})
			//FSM may be reset already from somewhere else, nothing we can do here anymore
			return
		}
		//retry End SW DL
		oFsm.mutexUpgradeParams.Lock()
		oFsm.delayEndSwDl = false //no more extra delay for the request
		oFsm.mutexUpgradeParams.Unlock()
		go func(a_pAFsm *AdapterFsm) {
			_ = a_pAFsm.pFsm.Event(upgradeEvContinueFinalize)
		}(pBaseFsm)
		return
	case success := <-oFsm.chReceiveExpectedResponse:
		logger.Debugw(ctx, "WaitEndDl stop  wait timer", log.Fields{"device-id": oFsm.deviceID})
		pBaseFsm := oFsm.pAdaptFsm
		if pBaseFsm == nil {
			logger.Errorw(ctx, "WaitEndDl abort: BaseFsm invalid", log.Fields{
				"device-id": oFsm.deviceID})
			//FSM may be reset already from somewhere else, nothing we can do here anymore
			return
		}
		if success {
			//answer received with ready indication
			//useAPIVersion43 may not conflict in concurrency in this state function
			if oFsm.useAPIVersion43 { // newer API usage requires verification of downloaded image version
				go func(a_pAFsm *AdapterFsm) {
					_ = a_pAFsm.pFsm.Event(upgradeEvCheckImageName)
				}(pBaseFsm)
			} else { // elder API usage does not support image version check -immediately consider download as successful
				if oFsm.activateImage {
					//immediate activation requested
					go func(a_pAFsm *AdapterFsm) {
						_ = a_pAFsm.pFsm.Event(upgradeEvRequestActivate)
					}(pBaseFsm)
				} else {
					//have to wait on explicit activation request
					go func(a_pAFsm *AdapterFsm) {
						_ = a_pAFsm.pFsm.Event(upgradeEvWaitForActivate)
					}(pBaseFsm)
				}
			}
			return
		}
		//timer was aborted
		oFsm.abortOnOmciError(ctx, true, voltha.ImageState_IMAGE_UNKNOWN) //no ImageState update
		return
	}
}

func (oFsm *OnuUpgradeFsm) enterCheckImageName(ctx context.Context, e *fsm.Event) {
	logger.Debugw(ctx, "OnuUpgradeFsm checking downloaded image name", log.Fields{
		"device-id": oFsm.deviceID, "me-id": oFsm.inactiveImageMeID})
	requestedAttributes := me.AttributeValueMap{"IsCommitted": 0, "IsActive": 0, "Version": ""}
	meInstance, err := oFsm.pOmciCC.sendGetMe(log.WithSpanFromContext(context.TODO(), ctx),
		me.SoftwareImageClassID, oFsm.inactiveImageMeID, requestedAttributes, oFsm.pDeviceHandler.pOpenOnuAc.omciTimeout,
		false, oFsm.pAdaptFsm.commChan)
	if err != nil {
		logger.Errorw(ctx, "OnuUpgradeFsm get Software Image ME result error",
			log.Fields{"device-id": oFsm.deviceID, "Error": err})
		oFsm.abortOnOmciError(ctx, true, voltha.ImageState_IMAGE_UNKNOWN) //no ImageState update
		return
	}
	oFsm.pLastTxMeInstance = meInstance
}

func (oFsm *OnuUpgradeFsm) enterActivateSw(ctx context.Context, e *fsm.Event) {
	logger.Infow(ctx, "OnuUpgradeFsm activate SW", log.Fields{
		"device-id": oFsm.deviceID, "me-id": oFsm.inactiveImageMeID})

	err := oFsm.pOmciCC.sendActivateSoftware(log.WithSpanFromContext(context.TODO(), ctx), oFsm.pDeviceHandler.pOpenOnuAc.omciTimeout, false,
		oFsm.pAdaptFsm.commChan, oFsm.inactiveImageMeID)
	if err != nil {
		logger.Errorw(ctx, "ActivateSw abort: can't send activate frame", log.Fields{
			"device-id": oFsm.deviceID, "error": err})
		oFsm.abortOnOmciError(ctx, true, voltha.ImageState_IMAGE_ACTIVATION_ABORTED)
		return
	}
	oFsm.mutexUpgradeParams.Lock()
	oFsm.volthaImageState = voltha.ImageState_IMAGE_ACTIVATING
	oFsm.mutexUpgradeParams.Unlock()
}

func (oFsm *OnuUpgradeFsm) enterCommitSw(ctx context.Context, e *fsm.Event) {
	logger.Debugw(ctx, "OnuUpgradeFsm start commit SW", log.Fields{
		"device-id": oFsm.deviceID, "me-id": oFsm.inactiveImageMeID})
	//any abort request (also conditional) is still regarded as valid as the commit indication might not be possible to verify
	// (which is a bit problematic as the ONU might already be in committed state,
	// in this case (committing failed) always 'onuimage list' should be used to verify the real state (if ONU is reachable))
	if activeImageID, err := oFsm.pDevEntry.GetActiveImageMeID(ctx); err == nil {
		oFsm.mutexUpgradeParams.Lock()
		if activeImageID == oFsm.inactiveImageMeID {
			inactiveImageID := oFsm.inactiveImageMeID
			logger.Infow(ctx, "OnuUpgradeFsm commit SW", log.Fields{
				"device-id": oFsm.deviceID, "me-id": inactiveImageID}) //more efficient activeImageID with above check
			oFsm.volthaImageState = voltha.ImageState_IMAGE_COMMITTING
			oFsm.mutexUpgradeParams.Unlock()
			err := oFsm.pOmciCC.sendCommitSoftware(log.WithSpanFromContext(context.TODO(), ctx), oFsm.pDeviceHandler.pOpenOnuAc.omciTimeout, false,
				oFsm.pAdaptFsm.commChan, inactiveImageID) //more efficient activeImageID with above check
			if err != nil {
				logger.Errorw(ctx, "CommitSw abort: can't send commit sw frame", log.Fields{
					"device-id": oFsm.deviceID, "error": err})
				oFsm.abortOnOmciError(ctx, true, voltha.ImageState_IMAGE_COMMIT_ABORTED)
				return
			}
			return
		}
		oFsm.mutexUpgradeParams.Unlock()
		logger.Errorw(ctx, "OnuUpgradeFsm active ImageId <> IdToCommit", log.Fields{
			"device-id": oFsm.deviceID, "active ID": activeImageID, "to commit ID": oFsm.inactiveImageMeID})
	} else {
		logger.Errorw(ctx, "OnuUpgradeFsm can't commit, no valid active image", log.Fields{
			"device-id": oFsm.deviceID})
	}
	oFsm.mutexUpgradeParams.Lock()
	oFsm.conditionalCancelRequested = false //any lingering conditional cancelRequest is superseded by this error
	oFsm.volthaDownloadState = voltha.ImageState_DOWNLOAD_FAILED
	oFsm.volthaDownloadReason = voltha.ImageState_CANCELLED_ON_ONU_STATE
	oFsm.volthaImageState = voltha.ImageState_IMAGE_COMMIT_ABORTED
	oFsm.mutexUpgradeParams.Unlock()
	//TODO!!!: possibly send event information for aborted upgrade (aborted by omci processing)??
	pBaseFsm := oFsm.pAdaptFsm
	// Can't call FSM Event directly, decoupling it
	go func(a_pAFsm *AdapterFsm) {
		_ = a_pAFsm.pFsm.Event(upgradeEvAbort)
	}(pBaseFsm)
}

func (oFsm *OnuUpgradeFsm) enterCheckCommitted(ctx context.Context, e *fsm.Event) {
	logger.Debugw(ctx, "OnuUpgradeFsm checking committed SW", log.Fields{
		"device-id": oFsm.deviceID, "me-id": oFsm.inactiveImageMeID})
	requestedAttributes := me.AttributeValueMap{"IsCommitted": 0, "IsActive": 0, "Version": ""}
	meInstance, err := oFsm.pOmciCC.sendGetMe(log.WithSpanFromContext(context.TODO(), ctx),
		me.SoftwareImageClassID, oFsm.inactiveImageMeID, requestedAttributes, oFsm.pDeviceHandler.pOpenOnuAc.omciTimeout, false, oFsm.pAdaptFsm.commChan)
	if err != nil {
		logger.Errorw(ctx, "OnuUpgradeFsm get Software Image ME result error",
			log.Fields{"device-id": oFsm.deviceID, "Error": err})
		oFsm.abortOnOmciError(ctx, true, voltha.ImageState_IMAGE_COMMIT_ABORTED)
		return
	}
	oFsm.pLastTxMeInstance = meInstance
}

func (oFsm *OnuUpgradeFsm) enterResetting(ctx context.Context, e *fsm.Event) {
	logger.Debugw(ctx, "OnuUpgradeFsm resetting", log.Fields{"device-id": oFsm.deviceID})

	// if the reset was conditionally requested
	if oFsm.conditionalCancelRequested {
		oFsm.mutexUpgradeParams.Lock()
		oFsm.volthaDownloadState = voltha.ImageState_DOWNLOAD_FAILED
		oFsm.volthaDownloadReason = voltha.ImageState_CANCELLED_ON_ONU_STATE
		oFsm.mutexUpgradeParams.Unlock()
	}

	// in case the download-to-ONU timer is still running - cancel it
	oFsm.mutexIsAwaitingOnuDlResponse.RLock()
	if oFsm.isWaitingForOnuDlResponse {
		oFsm.mutexIsAwaitingOnuDlResponse.RUnlock()
		//use channel to indicate that the download response waiting shall be aborted for this device (channel)
		oFsm.chOnuDlReady <- false
	} else {
		oFsm.mutexIsAwaitingOnuDlResponse.RUnlock()
	}

	pConfigupgradeStateAFsm := oFsm.pAdaptFsm
	if pConfigupgradeStateAFsm != nil {
		// abort running message processing
		fsmAbortMsg := Message{
			Type: TestMsg,
			Data: TestMessage{
				TestMessageVal: AbortMessageProcessing,
			},
		}
		pConfigupgradeStateAFsm.commChan <- fsmAbortMsg

		//try to restart the FSM to 'disabled'
		// Can't call FSM Event directly, decoupling it
		go func(a_pAFsm *AdapterFsm) {
			if a_pAFsm != nil && a_pAFsm.pFsm != nil {
				_ = a_pAFsm.pFsm.Event(upgradeEvRestart)
			}
		}(pConfigupgradeStateAFsm)
	}
}

func (oFsm *OnuUpgradeFsm) enterDisabled(ctx context.Context, e *fsm.Event) {
	logger.Debugw(ctx, "OnuUpgradeFsm enters disabled state", log.Fields{"device-id": oFsm.deviceID})
	// no need to flush possible channels here, Upgrade FSM will be completely removed, garbage collector should find its way
	if oFsm.pDeviceHandler != nil {
		//request removal of 'reference' in the Handler (completely clear the FSM and its data)
		pLastUpgradeImageState := &voltha.ImageState{
			Version:       oFsm.imageVersion,
			DownloadState: oFsm.volthaDownloadState,
			Reason:        oFsm.volthaDownloadReason,
			ImageState:    oFsm.volthaImageState,
		}
		go oFsm.pDeviceHandler.removeOnuUpgradeFsm(ctx, pLastUpgradeImageState)
	}
}

func (oFsm *OnuUpgradeFsm) processOmciUpgradeMessages(ctx context.Context) { //ctx context.Context?
	logger.Debugw(ctx, "Start OnuUpgradeFsm Msg processing", log.Fields{"for device-id": oFsm.deviceID})
loop:
	for {
		// case <-ctx.Done():
		// 	logger.Info(ctx,"MibSync Msg", log.Fields{"Message handling canceled via context for device-id": oFsm.deviceID})
		// 	break loop
		message, ok := <-oFsm.pAdaptFsm.commChan
		if !ok {
			logger.Info(ctx, "OnuUpgradeFsm Rx Msg - could not read from channel", log.Fields{"device-id": oFsm.deviceID})
			// but then we have to ensure a restart of the FSM as well - as exceptional procedure
			oFsm.abortOnOmciError(ctx, true, voltha.ImageState_IMAGE_UNKNOWN) //no ImageState update
			break loop
		}
		logger.Debugw(ctx, "OnuUpgradeFsm Rx Msg", log.Fields{"device-id": oFsm.deviceID})

		switch message.Type {
		case TestMsg:
			msg, _ := message.Data.(TestMessage)
			if msg.TestMessageVal == AbortMessageProcessing {
				logger.Infow(ctx, "OnuUpgradeFsm abort ProcessMsg", log.Fields{"for device-id": oFsm.deviceID})
				break loop
			}
			logger.Warnw(ctx, "OnuUpgradeFsm unknown TestMessage", log.Fields{"device-id": oFsm.deviceID, "MessageVal": msg.TestMessageVal})
		case OMCI:
			msg, _ := message.Data.(OmciMessage)
			oFsm.handleOmciOnuUpgradeMessage(ctx, msg)
		default:
			logger.Warn(ctx, "OnuUpgradeFsm Rx unknown message", log.Fields{"device-id": oFsm.deviceID,
				"message.Type": message.Type})
		}
	}
	logger.Infow(ctx, "End OnuUpgradeFsm Msg processing", log.Fields{"device-id": oFsm.deviceID})
}

//nolint: gocyclo
func (oFsm *OnuUpgradeFsm) handleOmciOnuUpgradeMessage(ctx context.Context, msg OmciMessage) {
	logger.Debugw(ctx, "Rx OMCI OnuUpgradeFsm Msg", log.Fields{"device-id": oFsm.deviceID,
		"msgType": msg.OmciMsg.MessageType})

	switch msg.OmciMsg.MessageType {
	case omci.StartSoftwareDownloadResponseType:
		{
			msgLayer := (*msg.OmciPacket).Layer(omci.LayerTypeStartSoftwareDownloadResponse)
			if msgLayer == nil {
				logger.Errorw(ctx, "Omci Msg layer could not be detected for StartSwDlResponse",
					log.Fields{"device-id": oFsm.deviceID})
				oFsm.abortOnOmciError(ctx, false, voltha.ImageState_IMAGE_DOWNLOADING)
				return
			}
			msgObj, msgOk := msgLayer.(*omci.StartSoftwareDownloadResponse)
			if !msgOk {
				logger.Errorw(ctx, "Omci Msg layer could not be assigned for StartSwDlResponse",
					log.Fields{"device-id": oFsm.deviceID})
				oFsm.abortOnOmciError(ctx, false, voltha.ImageState_IMAGE_DOWNLOADING)
				return
			}
			logger.Debugw(ctx, "OnuUpgradeFsm StartSwDlResponse data", log.Fields{
				"device-id": oFsm.deviceID, "data-fields": msgObj})
			if msgObj.Result != me.Success {
				logger.Errorw(ctx, "OnuUpgradeFsm StartSwDlResponse result error - later: drive FSM to abort state ?",
					log.Fields{"device-id": oFsm.deviceID, "Error": msgObj.Result})
				oFsm.abortOnOmciError(ctx, false, voltha.ImageState_IMAGE_DOWNLOADING)
				return
			}

			oFsm.mutexUpgradeParams.Lock()
			if msgObj.EntityInstance == oFsm.inactiveImageMeID {
				logger.Debugw(ctx, "Expected StartSwDlResponse received", log.Fields{"device-id": oFsm.deviceID})
				if msgObj.WindowSize != oFsm.omciDownloadWindowSizeLimit {
					// also response WindowSize = 0 is a valid number for used Window size 1
					logger.Debugw(ctx, "different StartSwDlResponse window size requested by ONU", log.Fields{
						"acceptedOnuWindowSizeLimit": msgObj.WindowSize, "device-id": oFsm.deviceID})
					oFsm.omciDownloadWindowSizeLimit = msgObj.WindowSize
				}
				oFsm.noOfWindows = oFsm.noOfSections / uint32(oFsm.omciDownloadWindowSizeLimit+1)
				if oFsm.noOfSections%uint32(oFsm.omciDownloadWindowSizeLimit+1) > 0 {
					oFsm.noOfWindows++
				}
				logger.Debugw(ctx, "OnuUpgradeFsm will use", log.Fields{
					"windows": oFsm.noOfWindows, "sections": oFsm.noOfSections,
					"at WindowSizeLimit": oFsm.omciDownloadWindowSizeLimit})
				oFsm.nextDownloadSectionsAbsolute = 0
				oFsm.nextDownloadSectionsWindow = 0
				oFsm.nextDownloadWindow = 0

				oFsm.mutexUpgradeParams.Unlock()
				_ = oFsm.pAdaptFsm.pFsm.Event(upgradeEvRxStartSwDownload)
				return
			}
			oFsm.mutexUpgradeParams.Unlock()
			logger.Errorw(ctx, "OnuUpgradeFsm StartSwDlResponse wrong ME instance: try again (later)?",
				log.Fields{"device-id": oFsm.deviceID, "ResponseMeId": msgObj.EntityInstance})
			oFsm.abortOnOmciError(ctx, false, voltha.ImageState_IMAGE_DOWNLOADING)
			return
		} //StartSoftwareDownloadResponseType
	case omci.DownloadSectionResponseType:
		{
			msgLayer := (*msg.OmciPacket).Layer(omci.LayerTypeDownloadSectionResponse)
			if msgLayer == nil {
				logger.Errorw(ctx, "Omci Msg layer could not be detected for DlSectionResponse",
					log.Fields{"device-id": oFsm.deviceID, "omci-message": msg.OmciMsg})
				oFsm.abortOnOmciError(ctx, false, voltha.ImageState_IMAGE_DOWNLOADING)
				return
			}
			msgObj, msgOk := msgLayer.(*omci.DownloadSectionResponse)
			if !msgOk {
				logger.Errorw(ctx, "Omci Msg layer could not be assigned for DlSectionResponse",
					log.Fields{"device-id": oFsm.deviceID})
				oFsm.abortOnOmciError(ctx, false, voltha.ImageState_IMAGE_DOWNLOADING)
				return
			}
			logger.Debugw(ctx, "OnuUpgradeFsm DlSectionResponse Data", log.Fields{
				"device-id": oFsm.deviceID, "data-fields": msgObj})
			if msgObj.Result != me.Success {
				logger.Errorw(ctx, "OnuUpgradeFsm DlSectionResponse result error - later: repeat window once?", //TODO!!!
					log.Fields{"device-id": oFsm.deviceID, "Error": msgObj.Result})
				oFsm.abortOnOmciError(ctx, false, voltha.ImageState_IMAGE_DOWNLOADING)
				return
			}
			oFsm.mutexUpgradeParams.Lock()
			if msgObj.EntityInstance == oFsm.inactiveImageMeID {
				sectionNumber := msgObj.SectionNumber
				logger.Infow(ctx, "DlSectionResponse received", log.Fields{
					"window section-number": sectionNumber, "window": oFsm.nextDownloadWindow, "device-id": oFsm.deviceID})

				oFsm.nextDownloadWindow++
				if oFsm.nextDownloadWindow >= oFsm.noOfWindows {
					if sectionNumber != oFsm.omciDownloadWindowSizeLast {
						logger.Errorw(ctx, "OnuUpgradeFsm DlSectionResponse section error last window - later: repeat window once?", //TODO!!!
							log.Fields{"device-id": oFsm.deviceID, "actual section": sectionNumber,
								"expected section": oFsm.omciDownloadWindowSizeLast})
						oFsm.mutexUpgradeParams.Unlock()
						oFsm.abortOnOmciError(ctx, false, voltha.ImageState_IMAGE_DOWNLOADING)
						return
					}
					oFsm.delayEndSwDl = true //ensure a delay for the EndSwDl message
					//CRC computation for all data bytes of the file
					imageCRC := crc32a.Checksum(oFsm.imageBuffer[:int(oFsm.origImageLength)]) //store internal for multiple usage
					//revert the retrieved CRC Byte Order (seems not to deliver NetworkByteOrder)
					var byteSlice []byte = make([]byte, 4)
					binary.LittleEndian.PutUint32(byteSlice, uint32(imageCRC))
					oFsm.imageCRC = binary.BigEndian.Uint32(byteSlice)
					oFsm.mutexUpgradeParams.Unlock()
					_ = oFsm.pAdaptFsm.pFsm.Event(upgradeEvEndSwDownload)
					return
				}
				if sectionNumber != oFsm.omciDownloadWindowSizeLimit {
					logger.Errorw(ctx, "OnuUpgradeFsm DlSectionResponse section error - later: repeat window once?", //TODO!!!
						log.Fields{"device-id": oFsm.deviceID, "actual-section": sectionNumber,
							"expected section": oFsm.omciDownloadWindowSizeLimit})
					oFsm.mutexUpgradeParams.Unlock()
					oFsm.abortOnOmciError(ctx, false, voltha.ImageState_IMAGE_DOWNLOADING)
					return
				}
				oFsm.nextDownloadSectionsWindow = 0
				oFsm.mutexUpgradeParams.Unlock()
				_ = oFsm.pAdaptFsm.pFsm.Event(upgradeEvContinueNextWindow)
				return
			}
			oFsm.mutexUpgradeParams.Unlock()
			logger.Errorw(ctx, "OnuUpgradeFsm Omci StartSwDlResponse wrong ME instance: try again (later)?",
				log.Fields{"device-id": oFsm.deviceID, "ResponseMeId": msgObj.EntityInstance})
			oFsm.abortOnOmciError(ctx, false, voltha.ImageState_IMAGE_DOWNLOADING)
			return
		} //DownloadSectionResponseType
	case omci.EndSoftwareDownloadResponseType:
		{
			msgLayer := (*msg.OmciPacket).Layer(omci.LayerTypeEndSoftwareDownloadResponse)
			if msgLayer == nil {
				logger.Errorw(ctx, "Omci Msg layer could not be detected for EndSwDlResponse",
					log.Fields{"device-id": oFsm.deviceID})
				oFsm.abortOnOmciError(ctx, false, voltha.ImageState_IMAGE_DOWNLOADING)
				return
			}
			msgObj, msgOk := msgLayer.(*omci.EndSoftwareDownloadResponse)
			if !msgOk {
				logger.Errorw(ctx, "Omci Msg layer could not be assigned for EndSwDlResponse",
					log.Fields{"device-id": oFsm.deviceID})
				oFsm.abortOnOmciError(ctx, false, voltha.ImageState_IMAGE_DOWNLOADING)
				return
			}
			logger.Debugw(ctx, "OnuUpgradeFsm EndSwDlResponse data", log.Fields{
				"device-id": oFsm.deviceID, "data-fields": msgObj})
			if msgObj.Result != me.Success {
				if msgObj.Result == me.DeviceBusy {
					//ONU indicates it is still processing the image - let the FSM just wait and then repeat the request
					logger.Debugw(ctx, "OnuUpgradeFsm EndSwDlResponse busy: waiting before sending new request", log.Fields{
						"device-id": oFsm.deviceID})
					return
				}
				logger.Errorw(ctx, "OnuUpgradeFsm EndSwDlResponse result error - later: drive FSM to abort state ?",
					log.Fields{"device-id": oFsm.deviceID, "Error": msgObj.Result})
				oFsm.abortOnOmciError(ctx, false, voltha.ImageState_IMAGE_DOWNLOADING)
				return
			}
			oFsm.mutexUpgradeParams.Lock()
			if msgObj.EntityInstance == oFsm.inactiveImageMeID {
				//EndSwDownloadSuccess is used to indicate 'DOWNLOAD_SUCCEEDED'
				oFsm.volthaDownloadState = voltha.ImageState_DOWNLOAD_SUCCEEDED
				if !oFsm.useAPIVersion43 {
					//in the older API version the image version check was not possible
					//  - assume new loaded image as valid-inactive immediately
					oFsm.volthaImageState = voltha.ImageState_IMAGE_INACTIVE
					oFsm.mutexUpgradeParams.Unlock()
					oFsm.mutexIsAwaitingOnuDlResponse.RLock()
					if oFsm.isWaitingForOnuDlResponse {
						oFsm.mutexIsAwaitingOnuDlResponse.RUnlock()
						//use non-blocking channel to indicate that the download to ONU was successful
						select {
						case oFsm.chOnuDlReady <- true:
						default:
						}
					} else {
						oFsm.mutexIsAwaitingOnuDlResponse.RUnlock()
					}
				} else {
					oFsm.mutexUpgradeParams.Unlock()
				}
				logger.Debugw(ctx, "Expected EndSwDlResponse received", log.Fields{"device-id": oFsm.deviceID})
				//use non-blocking channel to let the FSM proceed from the waitState
				select {
				case oFsm.chReceiveExpectedResponse <- true:
				default:
				}
				return
			}
			oFsm.mutexUpgradeParams.Unlock()
			logger.Errorw(ctx, "OnuUpgradeFsm StartSwDlResponse wrong ME instance: try again (later)?",
				log.Fields{"device-id": oFsm.deviceID, "ResponseMeId": msgObj.EntityInstance})
			oFsm.abortOnOmciError(ctx, false, voltha.ImageState_IMAGE_DOWNLOADING)
			return
		} //EndSoftwareDownloadResponseType
	case omci.ActivateSoftwareResponseType:
		{
			msgLayer := (*msg.OmciPacket).Layer(omci.LayerTypeActivateSoftwareResponse)
			if msgLayer == nil {
				logger.Errorw(ctx, "Omci Msg layer could not be detected for ActivateSw",
					log.Fields{"device-id": oFsm.deviceID})
				oFsm.abortOnOmciError(ctx, false, voltha.ImageState_IMAGE_ACTIVATION_ABORTED)
				return
			}
			msgObj, msgOk := msgLayer.(*omci.ActivateSoftwareResponse)
			if !msgOk {
				logger.Errorw(ctx, "Omci Msg layer could not be assigned for ActivateSw",
					log.Fields{"device-id": oFsm.deviceID})
				oFsm.abortOnOmciError(ctx, false, voltha.ImageState_IMAGE_ACTIVATION_ABORTED)
				return
			}
			logger.Debugw(ctx, "OnuUpgradeFsm ActivateSwResponse data", log.Fields{
				"device-id": oFsm.deviceID, "data-fields": msgObj})
			if msgObj.Result != me.Success {
				logger.Errorw(ctx, "OnuUpgradeFsm ActivateSwResponse result error - later: drive FSM to abort state ?",
					log.Fields{"device-id": oFsm.deviceID, "Error": msgObj.Result})
				oFsm.abortOnOmciError(ctx, false, voltha.ImageState_IMAGE_ACTIVATION_ABORTED)
				return
			}
			oFsm.mutexUpgradeParams.Lock()
			if msgObj.EntityInstance == oFsm.inactiveImageMeID {
				// the image is regarded as active really only after ONU reboot and according indication (ONU down/up procedure)
				oFsm.mutexUpgradeParams.Unlock()
				logger.Infow(ctx, "Expected ActivateSwResponse received",
					log.Fields{"device-id": oFsm.deviceID, "commit": oFsm.commitImage})
				if oFsm.commitImage {
					_ = oFsm.pAdaptFsm.pFsm.Event(upgradeEvWaitForCommit)
				} else {
					_ = oFsm.pAdaptFsm.pFsm.Event(upgradeEvActivationDone) // let the FSM wait for external commit request
				}
				return
			}
			oFsm.mutexUpgradeParams.Unlock()
			logger.Errorw(ctx, "OnuUpgradeFsm ActivateSwResponse wrong ME instance: abort",
				log.Fields{"device-id": oFsm.deviceID, "ResponseMeId": msgObj.EntityInstance})
			oFsm.abortOnOmciError(ctx, false, voltha.ImageState_IMAGE_ACTIVATION_ABORTED)
			return
		} //ActivateSoftwareResponseType
	case omci.CommitSoftwareResponseType:
		{
			msgLayer := (*msg.OmciPacket).Layer(omci.LayerTypeCommitSoftwareResponse)
			if msgLayer == nil {
				logger.Errorw(ctx, "Omci Msg layer could not be detected for CommitResponse",
					log.Fields{"device-id": oFsm.deviceID})
				oFsm.abortOnOmciError(ctx, false, voltha.ImageState_IMAGE_COMMIT_ABORTED)
				return
			}
			msgObj, msgOk := msgLayer.(*omci.CommitSoftwareResponse)
			if !msgOk {
				logger.Errorw(ctx, "Omci Msg layer could not be assigned for CommitResponse",
					log.Fields{"device-id": oFsm.deviceID})
				oFsm.abortOnOmciError(ctx, false, voltha.ImageState_IMAGE_COMMIT_ABORTED)
				return
			}
			if msgObj.Result != me.Success {
				logger.Errorw(ctx, "OnuUpgradeFsm SwImage CommitResponse result error - later: drive FSM to abort state ?",
					log.Fields{"device-id": oFsm.deviceID, "Error": msgObj.Result})
				oFsm.abortOnOmciError(ctx, false, voltha.ImageState_IMAGE_COMMIT_ABORTED)
				return
			}
			oFsm.mutexUpgradeParams.RLock()
			if msgObj.EntityInstance == oFsm.inactiveImageMeID {
				oFsm.mutexUpgradeParams.RUnlock()
				logger.Debugw(ctx, "OnuUpgradeFsm Expected SwImage CommitResponse received", log.Fields{"device-id": oFsm.deviceID})
				//verifying committed image
				_ = oFsm.pAdaptFsm.pFsm.Event(upgradeEvCheckCommitted)
				return
			}
			oFsm.mutexUpgradeParams.RUnlock()
			logger.Errorw(ctx, "OnuUpgradeFsm SwImage CommitResponse  wrong ME instance: abort",
				log.Fields{"device-id": oFsm.deviceID, "ResponseMeId": msgObj.EntityInstance})
			oFsm.abortOnOmciError(ctx, false, voltha.ImageState_IMAGE_COMMIT_ABORTED)
			return
		} //CommitSoftwareResponseType
	case omci.GetResponseType:
		{
			msgLayer := (*msg.OmciPacket).Layer(omci.LayerTypeGetResponse)
			if msgLayer == nil {
				logger.Errorw(ctx, "Omci Msg layer could not be detected for SwImage GetResponse",
					log.Fields{"device-id": oFsm.deviceID})
				oFsm.abortOnOmciError(ctx, false, voltha.ImageState_IMAGE_COMMIT_ABORTED)
				return
			}
			msgObj, msgOk := msgLayer.(*omci.GetResponse)
			if !msgOk {
				logger.Errorw(ctx, "Omci Msg layer could not be assigned for SwImage GetResponse",
					log.Fields{"device-id": oFsm.deviceID})
				oFsm.abortOnOmciError(ctx, false, voltha.ImageState_IMAGE_COMMIT_ABORTED)
				return
			}
			logger.Debugw(ctx, "OnuUpgradeFsm SwImage GetResponse data", log.Fields{
				"device-id": oFsm.deviceID, "data-fields": msgObj})
			if msgObj.EntityClass == oFsm.pLastTxMeInstance.GetClassID() &&
				msgObj.EntityInstance == oFsm.pLastTxMeInstance.GetEntityID() {
				if msgObj.Result != me.Success {
					logger.Errorw(ctx, "OnuUpgradeFsm SwImage GetResponse result error - later: drive FSM to abort state ?",
						log.Fields{"device-id": oFsm.deviceID, "Error": msgObj.Result})
					oFsm.abortOnOmciError(ctx, false, voltha.ImageState_IMAGE_COMMIT_ABORTED)
					return
				}
			} else {
				logger.Warnw(ctx, "OnuUpgradeFsm SwImage unexpected Entity GetResponse data - ignore",
					log.Fields{"device-id": oFsm.deviceID})
				return
			}

			meAttributes := msgObj.Attributes
			imageIsCommitted := meAttributes["IsCommitted"].(uint8)
			imageIsActive := meAttributes["IsActive"].(uint8)
			imageVersion := TrimStringFromMeOctet(meAttributes["Version"])
			logger.Debugw(ctx, "OnuUpgradeFsm - GetResponse Data for SoftwareImage",
				log.Fields{"device-id": oFsm.deviceID, "entityID": msgObj.EntityInstance,
					"version": imageVersion, "isActive": imageIsActive, "isCommitted": imageIsCommitted})

			if oFsm.pAdaptFsm.pFsm.Current() == upgradeStCheckImageName {
				//image name check after EndSwDownload, this state (and block) can only be taken if APIVersion43 is used
				oFsm.mutexUpgradeParams.Lock()
				if msgObj.EntityInstance == oFsm.inactiveImageMeID && imageIsActive == swIsInactive &&
					imageIsCommitted == swIsUncommitted {
					if imageVersion != oFsm.imageVersion {
						//new stored inactive version indicated on OMCI from ONU is not the expected version
						logger.Errorw(ctx, "OnuUpgradeFsm SwImage GetResponse version indication not matching requested upgrade",
							log.Fields{"device-id": oFsm.deviceID, "ResponseMeId": msgObj.EntityInstance,
								"onu-version": imageVersion, "expected-version": oFsm.imageVersion})
						oFsm.volthaDownloadState = voltha.ImageState_DOWNLOAD_FAILED         //not the expected image was downloaded
						oFsm.volthaDownloadReason = voltha.ImageState_CANCELLED_ON_ONU_STATE //something like 'UNEXPECTED_VERSION' would be better - proto def
						oFsm.volthaImageState = voltha.ImageState_IMAGE_UNKNOWN              //something like 'DOWNLOADED' would be better - proto def
						oFsm.mutexUpgradeParams.Unlock()
						//stop the running ONU download timer
						oFsm.mutexIsAwaitingOnuDlResponse.RLock()
						if oFsm.isWaitingForOnuDlResponse {
							oFsm.mutexIsAwaitingOnuDlResponse.RUnlock()
							//use channel to indicate that the download to ONU was not successful
							oFsm.chOnuDlReady <- false
						} else {
							oFsm.mutexIsAwaitingOnuDlResponse.RUnlock()
						}
						// TODO!!!: error treatment?
						//TODO!!!: possibly send event information for aborted upgrade (aborted by wrong version)?
						_ = oFsm.pAdaptFsm.pFsm.Event(upgradeEvAbort)
						return
					}
					//with APIVersion43 this is the point to consider the newly loaded image as valid (and inactive)
					oFsm.volthaImageState = voltha.ImageState_IMAGE_INACTIVE
					//store the new inactive version to onuSwImageIndications (to keep them in sync)
					oFsm.pDevEntry.modifySwImageInactiveVersion(ctx, oFsm.imageVersion)
					//proceed within upgrade FSM
					if oFsm.activateImage {
						//immediate activation requested
						oFsm.mutexUpgradeParams.Unlock()
						logger.Debugw(ctx, "OnuUpgradeFsm - expected ONU image version indicated by the ONU, continue with activation",
							log.Fields{"device-id": oFsm.deviceID})
						_ = oFsm.pAdaptFsm.pFsm.Event(upgradeEvRequestActivate)
					} else {
						//have to wait on explicit activation request
						// but a previously requested download activity (without activation) was successful here
						oFsm.volthaDownloadState = voltha.ImageState_DOWNLOAD_SUCCEEDED
						oFsm.mutexUpgradeParams.Unlock()
						logger.Infow(ctx, "OnuUpgradeFsm - expected ONU image version indicated by the ONU, wait for activate request",
							log.Fields{"device-id": oFsm.deviceID})
						_ = oFsm.pAdaptFsm.pFsm.Event(upgradeEvWaitForActivate)
					}
					oFsm.mutexIsAwaitingOnuDlResponse.RLock()
					if oFsm.isWaitingForOnuDlResponse {
						oFsm.mutexIsAwaitingOnuDlResponse.RUnlock()
						//use channel to indicate that the download to ONU was successful
						oFsm.chOnuDlReady <- true
					} else {
						oFsm.mutexIsAwaitingOnuDlResponse.RUnlock()
					}
					return
				}
				//not the expected image/image state
				oFsm.volthaDownloadState = voltha.ImageState_DOWNLOAD_FAILED
				oFsm.volthaDownloadReason = voltha.ImageState_CANCELLED_ON_ONU_STATE
				oFsm.volthaImageState = voltha.ImageState_IMAGE_UNKNOWN //real image state not known
				oFsm.mutexUpgradeParams.Unlock()
				logger.Errorw(ctx, "OnuUpgradeFsm SwImage GetResponse indications not matching requested upgrade",
					log.Fields{"device-id": oFsm.deviceID, "ResponseMeId": msgObj.EntityInstance})
				// TODO!!!: error treatment?
				//TODO!!!: possibly send event information for aborted upgrade (aborted by ONU state indication)?
				_ = oFsm.pAdaptFsm.pFsm.Event(upgradeEvAbort)
				return
			}

			//assumed only relevant state here is upgradeStCheckCommitted
			oFsm.mutexUpgradeParams.Lock()
			oFsm.conditionalCancelRequested = false //getting here any set (conditional) cancelRequest is not relevant anymore
			if msgObj.EntityInstance == oFsm.inactiveImageMeID && imageIsActive == swIsActive {
				//a check on the delivered image version is not done, the ONU delivered version might be different from what might have been
				//  indicated in the download image version string (version must be part of the image content itself)
				//  so checking that might be quite unreliable
				//but with new API this was changed, assumption is that omci image version is known at download request and exactly that is used
				//  in all the API references, so it can and should be checked here now
				if oFsm.useAPIVersion43 {
					if imageVersion != oFsm.imageVersion {
						//new active version indicated on OMCI from ONU is not the expected version
						logger.Errorw(ctx, "OnuUpgradeFsm image-version not matching the requested upgrade",
							log.Fields{"device-id": oFsm.deviceID, "ResponseMeId": msgObj.EntityInstance,
								"onu-version": imageVersion, "expected-version": oFsm.imageVersion})
						// TODO!!!: error treatment?
						//TODO!!!: possibly send event information for aborted upgrade (aborted by wrong version)?
						oFsm.volthaDownloadState = voltha.ImageState_DOWNLOAD_FAILED         //not the expected image was committed
						oFsm.volthaDownloadReason = voltha.ImageState_CANCELLED_ON_ONU_STATE //something like 'UNEXPECTED_VERSION' would be better - proto def
						oFsm.volthaImageState = voltha.ImageState_IMAGE_UNKNOWN              //expected image not known
						oFsm.mutexUpgradeParams.Unlock()
						_ = oFsm.pAdaptFsm.pFsm.Event(upgradeEvAbort)
						return
					}
					logger.Debugw(ctx, "OnuUpgradeFsm - expected ONU image version indicated by the ONU",
						log.Fields{"device-id": oFsm.deviceID})
				}
				if imageIsCommitted == swIsCommitted {
					oFsm.volthaDownloadState = voltha.ImageState_DOWNLOAD_SUCCEEDED
					oFsm.volthaImageState = voltha.ImageState_IMAGE_COMMITTED
					//store the new commit flag to onuSwImageIndications (to keep them in sync)
					oFsm.pDevEntry.modifySwImageActiveCommit(ctx, imageIsCommitted)
					logger.Infow(ctx, "requested SW image committed, releasing OnuUpgrade", log.Fields{"device-id": oFsm.deviceID})
					//deviceProcStatusUpdate not used anymore,
					// replaced by transferring the last (more) upgrade state information within removeOnuUpgradeFsm
					oFsm.mutexUpgradeParams.Unlock()
					//releasing the upgrade FSM on success
					_ = oFsm.pAdaptFsm.pFsm.Event(upgradeEvAbort)
					return
				}
				//if not committed, abort upgrade as failed. There is no implementation here that would trigger this test again
			}
			oFsm.volthaDownloadState = voltha.ImageState_DOWNLOAD_FAILED
			oFsm.volthaDownloadReason = voltha.ImageState_CANCELLED_ON_ONU_STATE
			oFsm.volthaImageState = voltha.ImageState_IMAGE_COMMIT_ABORTED
			oFsm.mutexUpgradeParams.Unlock()
			logger.Errorw(ctx, "OnuUpgradeFsm SwImage GetResponse indications not matching requested upgrade",
				log.Fields{"device-id": oFsm.deviceID, "ResponseMeId": msgObj.EntityInstance})
			// TODO!!!: error treatment?
			//TODO!!!: possibly send event information for aborted upgrade (aborted by omci processing)??
			_ = oFsm.pAdaptFsm.pFsm.Event(upgradeEvAbort)
			return
		} //GetResponseType
	default:
		{
			logger.Errorw(ctx, "Rx OMCI unhandled MsgType",
				log.Fields{"omciMsgType": msg.OmciMsg.MessageType, "device-id": oFsm.deviceID})
			return
		}
	}
}

//abortOnOmciError aborts the upgrade processing with OMCI_TRANSFER_ERROR indication
func (oFsm *OnuUpgradeFsm) abortOnOmciError(ctx context.Context, aAsync bool,
	aImageState voltha.ImageState_ImageActivationState) {
	oFsm.mutexUpgradeParams.Lock()
	oFsm.conditionalCancelRequested = false //any conditional cancelRequest is superseded by this abortion
	oFsm.volthaDownloadState = voltha.ImageState_DOWNLOAD_FAILED
	oFsm.volthaDownloadReason = voltha.ImageState_OMCI_TRANSFER_ERROR
	if aImageState != voltha.ImageState_IMAGE_UNKNOWN {
		// update image state only in case some explicite state is given (otherwise the existing state is used)
		oFsm.volthaImageState = aImageState
	}
	oFsm.mutexUpgradeParams.Unlock()
	//TODO!!!: possibly send event information for aborted upgrade (aborted by omci processing)??
	if oFsm.pAdaptFsm != nil {
		var err error
		if aAsync { //asynchronous call requested to ensure state transition
			go func(a_pAFsm *AdapterFsm) {
				if a_pAFsm.pFsm != nil {
					err = oFsm.pAdaptFsm.pFsm.Event(upgradeEvAbort)
				}
			}(oFsm.pAdaptFsm)
		} else {
			if oFsm.pAdaptFsm.pFsm != nil {
				err = oFsm.pAdaptFsm.pFsm.Event(upgradeEvAbort)
			}
		}
		if err != nil {
			logger.Warnw(ctx, "onu upgrade fsm could not abort on omci error", log.Fields{
				"device-id": oFsm.deviceID, "error": err})
		}
	}
}

//waitOnDownloadToAdapterReady state can only be reached with useAPIVersion43 (usage of pFileManager)
//  precondition: mutexIsAwaitingAdapterDlResponse is lockek on call
func (oFsm *OnuUpgradeFsm) waitOnDownloadToAdapterReady(ctx context.Context, aSyncChannel chan<- struct{},
	aWaitChannel chan bool) {
	oFsm.mutexIsAwaitingAdapterDlResponse.Lock()
	downloadToAdapterTimeout := oFsm.pFileManager.GetDownloadTimeout(ctx)
	oFsm.isWaitingForAdapterDlResponse = true
	oFsm.mutexIsAwaitingAdapterDlResponse.Unlock()
	aSyncChannel <- struct{}{}
	select {
	// maybe be also some outside cancel (but no context modeled for the moment ...)
	// case <-ctx.Done():
	// 		logger.Infow("OnuUpgradeFsm-waitOnDownloadToAdapterReady canceled", log.Fields{"for device-id": oFsm.deviceID})
	case <-time.After(downloadToAdapterTimeout): //10s should be enough for downloading some image to the adapter
		logger.Warnw(ctx, "OnuUpgradeFsm Waiting-adapter-download timeout", log.Fields{
			"for device-id": oFsm.deviceID, "image-id": oFsm.imageIdentifier, "timeout": downloadToAdapterTimeout})
		oFsm.pFileManager.RemoveReadyRequest(ctx, oFsm.imageIdentifier, aWaitChannel)
		oFsm.mutexIsAwaitingAdapterDlResponse.Lock()
		oFsm.isWaitingForAdapterDlResponse = false
		oFsm.mutexIsAwaitingAdapterDlResponse.Unlock()
		oFsm.abortOnOmciError(ctx, true, voltha.ImageState_IMAGE_UNKNOWN) //no ImageState update
		return

	case success := <-aWaitChannel:
		if success {
			logger.Debugw(ctx, "OnuUpgradeFsm image-downloaded received", log.Fields{"device-id": oFsm.deviceID})
			oFsm.mutexIsAwaitingAdapterDlResponse.Lock()
			oFsm.isWaitingForAdapterDlResponse = false
			oFsm.mutexIsAwaitingAdapterDlResponse.Unlock()
			//let the upgrade process proceed
			pUpgradeFsm := oFsm.pAdaptFsm
			if pUpgradeFsm != nil {
				_ = pUpgradeFsm.pFsm.Event(upgradeEvPrepareSwDownload)
			} else {
				logger.Errorw(ctx, "pUpgradeFsm is nil", log.Fields{"device-id": oFsm.deviceID})
			}
			return
		}
		// waiting was aborted (probably on external request)
		logger.Debugw(ctx, "OnuUpgradeFsm Waiting-adapter-download aborted", log.Fields{"device-id": oFsm.deviceID})
		oFsm.pFileManager.RemoveReadyRequest(ctx, oFsm.imageIdentifier, aWaitChannel)
		oFsm.mutexIsAwaitingAdapterDlResponse.Lock()
		oFsm.isWaitingForAdapterDlResponse = false
		oFsm.mutexIsAwaitingAdapterDlResponse.Unlock()
		//the upgrade process has to be aborted
		oFsm.abortOnOmciError(ctx, true, voltha.ImageState_IMAGE_UNKNOWN) //no ImageState update
		return
	}
}

//waitOnDownloadToOnuReady state can only be reached with useAPIVersion43 (usage of pFileManager)
func (oFsm *OnuUpgradeFsm) waitOnDownloadToOnuReady(ctx context.Context, aWaitChannel chan bool) {
	downloadToOnuTimeout := time.Duration(1+(oFsm.imageLength/0x400000)) * oFsm.downloadToOnuTimeout4MB
	logger.Debugw(ctx, "OnuUpgradeFsm start download-to-ONU timer", log.Fields{"device-id": oFsm.deviceID,
		"duration": downloadToOnuTimeout})
	oFsm.mutexIsAwaitingOnuDlResponse.Lock()
	oFsm.isWaitingForOnuDlResponse = true
	oFsm.mutexIsAwaitingOnuDlResponse.Unlock()
	select {
	// maybe be also some outside cancel (but no context modeled for the moment ...)
	// case <-ctx.Done():
	// 		logger.Infow("OnuUpgradeFsm-waitOnDownloadToOnuReady canceled", log.Fields{"for device-id": oFsm.deviceID})
	case <-time.After(downloadToOnuTimeout): //using an image-size depending timout (in minutes)
		logger.Warnw(ctx, "OnuUpgradeFsm Waiting-ONU-download timeout", log.Fields{
			"for device-id": oFsm.deviceID, "image-id": oFsm.imageIdentifier, "timeout": downloadToOnuTimeout})
		oFsm.mutexIsAwaitingOnuDlResponse.Lock()
		oFsm.isWaitingForOnuDlResponse = false
		oFsm.mutexIsAwaitingOnuDlResponse.Unlock()
		//the upgrade process has to be aborted
		oFsm.abortOnOmciError(ctx, true, voltha.ImageState_IMAGE_UNKNOWN) //no ImageState update
		return

	case success := <-aWaitChannel:
		if success {
			logger.Debugw(ctx, "OnuUpgradeFsm image-downloaded on ONU received", log.Fields{"device-id": oFsm.deviceID})
			oFsm.mutexIsAwaitingOnuDlResponse.Lock()
			oFsm.isWaitingForOnuDlResponse = false
			oFsm.mutexIsAwaitingOnuDlResponse.Unlock()
			//all fine, let the FSM proceed like defined from the sender of this event
			return
		}
		// waiting was aborted (assumed here to be caused by
		//   error detection or cancel at download after upgrade FSM reset/abort)
		logger.Debugw(ctx, "OnuUpgradeFsm Waiting-ONU-download aborted", log.Fields{"device-id": oFsm.deviceID})
		oFsm.mutexIsAwaitingOnuDlResponse.Lock()
		oFsm.isWaitingForOnuDlResponse = false
		oFsm.mutexIsAwaitingOnuDlResponse.Unlock()
		return
	}
}