[嵌入式]STM32CubeIDE SD卡 使用DMA问题

STM32CubeIDE　配置　SD模块并使用DMA 如下图， 比较简单
只用了dma２-channel4,

重写两个　__weak　函数：
BSP_SD_WriteBlocks　和　BSP_SD_ReadBlocks
（自动生成的代码sd_diskio.c　中使用的是这两个函数,）

uint8_t BSP_SD_ReadBlocks(uint32_t *pData, uint32_t ReadAddr, uint32_t NumOfBlocks, uint32_t Timeout)
{
  uint8_t sd_state = MSD_OK;
  if (HAL_SD_ReadBlocks_DMA(&hsd, (uint8_t *)pData, ReadAddr, NumOfBlocks) != HAL_OK)
  {
    sd_state = MSD_ERROR;
  }

  return sd_state;
}

uint8_t BSP_SD_WriteBlocks(uint32_t *pData, uint32_t WriteAddr, uint32_t NumOfBlocks, uint32_t Timeout)
{
  uint8_t sd_state = MSD_OK;
  if (HAL_SD_WriteBlocks_DMA(&hsd, (uint8_t *)pData, WriteAddr, NumOfBlocks) != HAL_OK)
  {
    sd_state = MSD_ERROR;
  }

  return sd_state;
}

编译成功后　实验发现读数据正确，　写操作数据没有真正写入。
使用中断方式进行对比，读写都没有问题， 看来还是DMA　问题。
查找源码，发现DMA配置方向有些问题，读写都是一样，那写操作就不对了。
确认问题所在就好办了：
每次操作前重新配置一下DMA参数即可， 当然需要DMA反初始化再重新初始化。

uint8_t BSP_SD_ReadBlocks(uint32_t *pData, uint32_t ReadAddr, uint32_t NumOfBlocks, uint32_t Timeout)
{
  uint8_t sd_state = MSD_OK;

  if (hdma_sdio.Init.Direction != DMA_PERIPH_TO_MEMORY)
  {
	  HAL_DMA_DeInit(&hdma_sdio);
	  hdma_sdio.Init.Direction = DMA_PERIPH_TO_MEMORY;
	  HAL_DMA_Init(&hdma_sdio);
  }

  if (HAL_SD_ReadBlocks_DMA(&hsd, (uint8_t *)pData, ReadAddr, NumOfBlocks) != HAL_OK)
  {
    sd_state = MSD_ERROR;
  }

  return sd_state;
}

uint8_t BSP_SD_WriteBlocks(uint32_t *pData, uint32_t WriteAddr, uint32_t NumOfBlocks, uint32_t Timeout)
{
  uint8_t sd_state = MSD_OK;

  if (hdma_sdio.Init.Direction != DMA_MEMORY_TO_PERIPH)
  {
	  HAL_DMA_DeInit(&hdma_sdio);
	  hdma_sdio.Init.Direction = DMA_MEMORY_TO_PERIPH;
	  HAL_DMA_Init(&hdma_sdio);
  }

  if (HAL_SD_WriteBlocks_DMA(&hsd, (uint8_t *)pData, WriteAddr, NumOfBlocks) != HAL_OK)
  {
    sd_state = MSD_ERROR;
  }

  return sd_state;
}