FreeRTOS+IO Zero Copy TX Fails at ioutilsGIVE_ZERO_COPY_MUTEX

Posted by kedar1993 on May 7, 2019

I am trying to use the Zero Copy TX Transfer Mode for Sending Data via UART peripheral but getting an assertion failure at ioutilsGIVE_ZERO_COPY_MUTEX. In my task, I am calling the the FreeRTOSwrite as follows: ~~~ const uint8t text[] = “————–rn”;

    xReturned = FreeRTOS_ioctl( xUART0Handle, ioctlOBTAIN_WRITE_MUTEX, (void *)(50UL/portTICK_RATE_MS));
    if( xReturned == pdTRUE )
    {
        xReturned = FreeRTOS_write(xUART0Handle, text, 16);
    }

~~~ Within the FreeRTOSwrite function, I am calling theioutilsINITIATE_ZERO_COPY_TX which initiates the transfer. Once the transfer is complete, the ISR for the peripheral is called where I am calling the `ioutilsGIVEZEROCOPYMUTEX’. This is where the assertion fails. ~~~ /* Normally a mutex would not be given from an interrupt, especially if there is a mutex holder, as priority inheritance makes no sense for an interrupts, only tasks. */ configASSERT(!((pxQueue->uxQueueType == queueQUEUE_IS_MUTEX) && (pxQueue->pxMutexHolder != NULL))); ~~~ I am not sure where I am going wrong and would appreciate any help. Thanks!