背景

1. 在閃光燈初始化階段客制化了一個buffer，下發到kernel的閃光燈驅動中用于保存讀取閃光燈寄存器的值。
2. 功能測試都是正常的，但是一旦開始批量跑產線老化測試會有1/4500左右概率的后主攝拍照卡住。
3. 定位根因是閃光燈初始化失敗，進一步原因就是客制化的buffer申請失敗。

具體流程

camxsensornode.cpp: ProcessingNodeFinalizeInitialization()
camxsensornode.cpp -> camxsensornode.cpp: m_pThreadManager->RegisterJobFamily();\n線程回調函數
camxsensornode.cpp -> camxsensornode.cpp: SensorThreadJobCallback()
camxsensornode.cpp -> camxsensornode.cpp: case SensorPostJobCommand::InitializeSensor:
camxsensornode.cpp -> camxsensornode.cpp: case SensorPostJobCommand::SubModulesCreate:
camxsensornode.cpp -> camxsensornode.cpp: SensorNode::CreateSensorSubmodules()
camxsensornode.cpp -> camxsensornode.cpp: SensorNode::CreateFlashResources()
camxsensornode.cpp -> camxnode.cpp:  CreateCmdBufferManager() x n
camxnode.cpp -> camxcmdbuffermanager.cpp : CmdBufferManager::Create()
camxcmdbuffermanager.cpp -> camxcmdbuffermanager.cpp: pCmdBufferManager->\nInitialize(pBufferManagerName, pParams);
camxcmdbuffermanager.cpp -> camxcmdbuffermanager.cpp: InitializePool();
camxcmdbuffermanager.cpp -> camxcslhw.cpp: CSLAlloc()
note right of camxcslhw.cpp: CSLAllocHW()...
camxcmdbuffermanager.cpp <-- camxcslhw.cpp
camxnode.cpp <-- camxcmdbuffermanager.cpp
camxsensornode.cpp <-- camxnode.cpp:
camxsensornode.cpp -> camxflash.cpp: Flash::Create(&createData)
camxflash.cpp -> camxflash.cpp: pCreateData->pFlash->Initialize(pCreateData)
camxflash.cpp -> camxflash.cpp: CreateInitializePacket()
camxflash.cpp -> camxcmdbuffermanager.cpp: m_pPacketManager->GetBuffer(&pResource)
camxcmdbuffermanager.cpp --> camxflash.cpp
camxflash.cpp -> camxflash.cpp: PopulateImageBuffer()
camxflash.cpp -> camximagebuffermanager.cpp: ImageBufferManager::Create(\n"FlashRegisterRead",&createData,\npFlashImageBufferManager)
camximagebuffermanager.cpp -> camximagebuffermanager.cpp: pImageBufferManager->Initialize();
camximagebuffermanager.cpp -> camxmempoolmgr.cpp: MemPoolMgr::RegisterBufferManager();
camxmempoolmgr.cpp -> camxmempoolmgr.cpp: pMemPoolMgr->RegisterNewMemPoolGroup();
camxmempoolmgr.cpp -> camxmempoolgroup.cpp: pMemPoolGroup->Initialize()
camxmempoolgroup.cpp --> camxmempoolmgr.cpp
camxmempoolmgr.cpp -> camxmempoolgroup.cpp: pMemPoolGroup->RegisterBufferManager();
camxmempoolgroup.cpp --> camxmempoolmgr.cpp
camxmempoolmgr.cpp --> camximagebuffermanager.cpp
note left of camxmempoolmgr.cpp: ------------先注冊內存池組，再進行初始化內存，通過FLAG來管理----------
camximagebuffermanager.cpp -> camximagebuffermanager.cpp: pImageBufferManager->InitializeBuffers();
camximagebuffermanager.cpp -> camximagebuffer.cpp: pBuffer->Allocate();
camximagebuffer.cpp -> camxmempoolmgr.cpp: MemPoolMgr::GetBufferFromPool();
camxmempoolmgr.cpp -> camxmempoolgroup.cpp: pMemPoolGroup->GetBufferFromPool()
camxmempoolgroup.cpp -> camxmempoolgroup.cpp: ActivateBufferManager();
camxmempoolgroup.cpp -> camxmempoolgroup.cpp: UpdateMemPoolGroupBufferCounts();
camxmempoolgroup.cpp -> camxmempoolgroup.cpp: AllocateBuffers(1);
camxmempoolgroup.cpp -> camxcsl.cpp: CSLAlloc(pBuffer->name,...)
camxcsl.cpp --> camxflash.cpp: 正確的分配完內存，可順利打開相機拍照。FlashRegisterRead申請的內存池組的flag，有概率被異步的TFE修改會導致分配內存失敗。可以通過添加標志位bNeedDedicatedBuffers=TRUE,來設置專屬內存組
note right of camxsensornode.cpp: 開啟新的線程
camxsensornode.cpp -> camxsensornode.cpp:SensorPostJobCommand::ConfigureSensor:
camxsensornode.cpp -> camxsensornode.cpp:SensorPostJobCommand::ReadRequest:...

正確的分配完內存，可順利打開相機拍照。FlashRegisterRead申請的內存池組的flag，有概率被異步的TFE修改會導致分配內存失敗。可以通過添加標志位bNeedDedicatedBuffers=TRUE,來設置專屬內存組

If self shrinking is disabled or heap type is EGL for this group, its better to have it as a dedicated
group for this Buffer Manager set m_bDedicatedGroup to TRUE in such case, so that IsMatchingGroup for
this group would fail for any future Buffer Manager registers

翻譯如下：