SDMMC DMA STM32-L476RG

DMA Channel doesn't work (+SDMMC)
Request Number: TECH040009

Type:   Technical
Severity:   Medium
State:  SOLUTION PROPOSED
Product :   Microcontrollers
STM32 32-bit ARM Cortex MCUs
STM32 Ultra Low Power MCUs
STM32L476RG
Description:    Package: STM32-L476RG (Nucleo)
Firmware: CubeMX 1.8.1

When using SDMMC (1-Bit) + DMA, the DMA2 Channel 4 doesn't seem to work.
When SDMMC_TX or _RX is put on channel 4, the SDMMC unit does not transmit anything (on cmd, data line, verified by oscilloscope).
When SDMMC_TX or _RX is put on channel 5, the SDMMC unit works as expected.

Thank you for any feedback!
Resolution Summary: SOLUTION PROPOSED BY SUPPORTER - 21/9/2017 11:54:26 :
---------------------------------------------------------------------------------
Dear Customer,

I could reproduce your issue on STM32L476G eval board creating a project from CubeMx.


I investigated looking at example on cubemx firmware project:
xxx\STM32Cube\Repository\STM32Cube_FW_L4_V1.8.1\Drivers\BSP\STM32L476G_EVAL\stm32l476g_eval_sd.c


I succeed to make work channel 4 and/or channel 5 for tx and rx by doing the following changes .

uint8_t BSP_SD_ReadBlocks_DMA(uint32_t *pData, uint32_t ReadAddr,
    uint32_t NumOfBlocks)
{
  HAL_DMA_Abort(&hdma_sdmmc1_tx);
  HAL_DMA_Abort(&hdma_sdmmc1_rx);

  /* Deinitialize the Channel for new transfer */
  HAL_DMA_DeInit(&hdma_sdmmc1_tx);
  HAL_DMA_DeInit(&hdma_sdmmc1_rx);

  HAL_DMA_Init(&hdma_sdmmc1_rx);
  ..

uint8_t BSP_SD_WriteBlocks_DMA(uint32_t *pData, uint32_t WriteAddr,
    uint32_t NumOfBlocks)
{
 uint32_t tickstart = HAL_GetTick();
  HAL_DMA_Abort(&hdma_sdmmc1_tx);
  HAL_DMA_Abort(&hdma_sdmmc1_rx);

  /* Deinitialize the Channel for new transfer */
  HAL_DMA_DeInit(&hdma_sdmmc1_tx);
  HAL_DMA_DeInit(&hdma_sdmmc1_rx);

  /* Configure the DMA Channel */
  HAL_DMA_Init(&hdma_sdmmc1_tx);

void DMA2_Channelx_IRQHandler(void)
{
  /* USER CODE BEGIN DMA2_Channel5_IRQn 0 */
  if((hsd1.Context == (SD_CONTEXT_DMA | SD_CONTEXT_READ_SINGLE_BLOCK)) ||
     (hsd1.Context == (SD_CONTEXT_DMA | SD_CONTEXT_READ_MULTIPLE_BLOCK)))
  {
     HAL_DMA_IRQHandler(&hdma_sdmmc1_rx);
  }
  else if((hsd1.Context == (SD_CONTEXT_DMA | SD_CONTEXT_WRITE_SINGLE_BLOCK)) ||
          (hsd1.Context == (SD_CONTEXT_DMA | SD_CONTEXT_WRITE_MULTIPLE_BLOCK)))
  {
      HAL_DMA_IRQHandler(&hdma_sdmmc1_tx);
  }

}