Conflicting definition of HAL_DCMI_Init?

[Dan Rose]

I'm experiencing a runtime crash when using DCMI in with `USE_HAL_DCMI_REGISTER_CALLBACKS`.

The crashing lines are

#if (USE_HAL_DCMI_REGISTER_CALLBACKS == 1)
    /*Call registered DCMI line event callback*/
    hdcmi->LineEventCallback(hdcmi);
#else  
    HAL_DCMI_LineEventCallback(hdcmi);
#endif /* USE_HAL_DCMI_REGISTER_CALLBACKS */

This seems to be caused by by conflicting definitions of `HAL_DCMI_Init`.

One definition is in `stm32f4xx_hal_dcmi.c`:

__weak HAL_StatusTypeDef HAL_DCMI_Init(DCMI_HandleTypeDef *hdcmi)
{
//...
  /* Init the DCMI Callback settings */
#if (USE_HAL_DCMI_REGISTER_CALLBACKS == 1)
    hdcmi->FrameEventCallback = HAL_DCMI_FrameEventCallback; /* Legacy weak FrameEventCallback  */ 
    hdcmi->VsyncEventCallback = HAL_DCMI_VsyncEventCallback; /* Legacy weak VsyncEventCallback  */ 
    hdcmi->LineEventCallback  = HAL_DCMI_LineEventCallback;  /* Legacy weak LineEventCallback   */  
    hdcmi->ErrorCallback      = HAL_DCMI_ErrorCallback;      /* Legacy weak ErrorCallback       */ 
    
    if(hdcmi->MspInitCallback == NULL)  
    {
      /* Legacy weak MspInit Callback        */
      hdcmi->MspInitCallback = HAL_DCMI_MspInit;
    }
    /* Initialize the low level hardware (MSP) */
    hdcmi->MspInitCallback(hdcmi);
#else  
    /* Init the low level hardware : GPIO, CLOCK, NVIC and DMA */
    HAL_DCMI_MspInit(hdcmi);
#endif /* (USE_HAL_DCMI_REGISTER_CALLBACKS) */

There is a conflicting definition that takes priority in `stm32f4xx_hal_dcmi_ex.c`, since it is not declared `__weak`:

HAL_StatusTypeDef HAL_DCMI_Init(DCMI_HandleTypeDef *hdcmi)

This initializer does *not* assign LineEventCallback, and doesn't even mention `USE_HAL_DCMI_REGISTER_CALLBACKS`

What's the deal? Is this user error or a bug in HAL?

[Khouloud OTHMAN]

Hello Dan Rose,

Thanks for your post. I have raised your feedback internally to be reviewed and treated accordingly to the priority. We will give you an update as soon as possible.

Thanks for your contribution.

Regards,

Khouloud.

[Khouloud OTHMAN]

Hello  Dan Rose,

Backing to this issue, could you please attach a trace / log file, it will be helpful to track the root-cause of the problem.

Thanks in advance,

Regards,

Khouloud.

[Dan Rose]

@Khouloud OTHMAN​ I don't have a trace/log file. The actual crash is a null pointer problem when it calls `hdcmi->LineEventCallback`, which is not initialized by the version of HAL_DCMI_Init in stm32f4xx_hal_dcmi_ex.c.