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[stm32][spi-dma] 只有传输数据超过一定长度才会使用DMA方式 

在传输数据为短小报文时，使用DMA模式反倒会慢
This commit is contained in:
Meco Man 2023-06-01 22:43:07 -04:00 committed by Man, Jianting (Meco)
parent 761a28e4d9
commit 22fb7152d9
1 changed files with 9 additions and 7 deletions
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16
bsp/stm32/libraries/HAL_Drivers/drv_spi.c
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@ -283,6 +283,8 @@ static rt_err_t stm32_spi_init(struct stm32_spi *spi_drv, struct rt_spi_configur
static rt_ssize_t spixfer(struct rt_spi_device *device, struct rt_spi_message *message)
{
#define DMA_TRANS_MIN_LEN 10 /* only buffer length >= DMA_TRANS_MIN_LEN will use DMA mode */
HAL_StatusTypeDef state = HAL_OK;
rt_size_t message_length, already_send_length;
rt_uint16_t send_length;
@ -341,7 +343,7 @@ static rt_ssize_t spixfer(struct rt_spi_device *device, struct rt_spi_message *m
#if defined(SOC_SERIES_STM32H7) || defined(SOC_SERIES_STM32F7)
rt_uint32_t* dma_buf = RT_NULL;
if ((spi_drv->spi_dma_flag & SPI_USING_TX_DMA_FLAG) && (spi_drv->spi_dma_flag & SPI_USING_RX_DMA_FLAG))
if ((spi_drv->spi_dma_flag & SPI_USING_TX_DMA_FLAG) && (spi_drv->spi_dma_flag & SPI_USING_RX_DMA_FLAG) && (send_length >= DMA_TRANS_MIN_LEN))
{
dma_buf = (rt_uint32_t *)rt_malloc_align(send_length,32);
if(send_buf)
@ -360,16 +362,16 @@ static rt_ssize_t spixfer(struct rt_spi_device *device, struct rt_spi_message *m
/* start once data exchange in DMA mode */
if (message->send_buf && message->recv_buf)
{
if ((spi_drv->spi_dma_flag & SPI_USING_TX_DMA_FLAG) && (spi_drv->spi_dma_flag & SPI_USING_RX_DMA_FLAG))
if ((spi_drv->spi_dma_flag & SPI_USING_TX_DMA_FLAG) && (spi_drv->spi_dma_flag & SPI_USING_RX_DMA_FLAG) && (send_length >= DMA_TRANS_MIN_LEN))
{
state = HAL_SPI_TransmitReceive_DMA(spi_handle, (uint8_t *)send_buf, (uint8_t *)recv_buf, send_length);
}
else if ((spi_drv->spi_dma_flag & SPI_USING_TX_DMA_FLAG))
else if ((spi_drv->spi_dma_flag & SPI_USING_TX_DMA_FLAG) && (send_length >= DMA_TRANS_MIN_LEN))
{
/* same as Tx ONLY. It will not receive SPI data any more. */
state = HAL_SPI_Transmit_DMA(spi_handle, (uint8_t *)send_buf, send_length);
}
else if ((spi_drv->spi_dma_flag & SPI_USING_RX_DMA_FLAG))
else if ((spi_drv->spi_dma_flag & SPI_USING_RX_DMA_FLAG) && (send_length >= DMA_TRANS_MIN_LEN))
{
state = HAL_ERROR;
LOG_E("It shoule be enabled both BSP_SPIx_TX_USING_DMA and BSP_SPIx_TX_USING_DMA flag, if wants to use SPI DMA Rx singly.");
@ -382,7 +384,7 @@ static rt_ssize_t spixfer(struct rt_spi_device *device, struct rt_spi_message *m
}
else if (message->send_buf)
{
if (spi_drv->spi_dma_flag & SPI_USING_TX_DMA_FLAG)
if ((spi_drv->spi_dma_flag & SPI_USING_TX_DMA_FLAG) && (send_length >= DMA_TRANS_MIN_LEN))
{
state = HAL_SPI_Transmit_DMA(spi_handle, (uint8_t *)send_buf, send_length);
}
@ -400,7 +402,7 @@ static rt_ssize_t spixfer(struct rt_spi_device *device, struct rt_spi_message *m
else if(message->recv_buf)
{
rt_memset((uint8_t *)recv_buf, 0xff, send_length);
if (spi_drv->spi_dma_flag & SPI_USING_RX_DMA_FLAG)
if ((spi_drv->spi_dma_flag & SPI_USING_RX_DMA_FLAG) && (send_length >= DMA_TRANS_MIN_LEN))
{
state = HAL_SPI_Receive_DMA(spi_handle, (uint8_t *)recv_buf, send_length);
}
@ -432,7 +434,7 @@ static rt_ssize_t spixfer(struct rt_spi_device *device, struct rt_spi_message *m
/* For simplicity reasons, this example is just waiting till the end of the
transfer, but application may perform other tasks while transfer operation
is ongoing. */
if (spi_drv->spi_dma_flag & (SPI_USING_TX_DMA_FLAG | SPI_USING_RX_DMA_FLAG))
if ((spi_drv->spi_dma_flag & (SPI_USING_TX_DMA_FLAG | SPI_USING_RX_DMA_FLAG)) && (send_length >= DMA_TRANS_MIN_LEN))
{
/* blocking the thread,and the other tasks can run */
if (rt_completion_wait(&spi_drv->cpt, 1000) != RT_EOK)