[bsp][stm32][spi] 优化H7 DMA数据非字节对齐的处理流程

bsp/stm32/libraries/HAL_Drivers/drivers/drv_spi.c

@@ -298,9 +298,13 @@ static rt_ssize_t spixfer(struct rt_spi_device *device, struct rt_spi_message *m
     if (message->cs_take && !(device->config.mode & RT_SPI_NO_CS) && (device->cs_pin != PIN_NONE))
     {
         if (device->config.mode & RT_SPI_CS_HIGH)
+        {
             rt_pin_write(device->cs_pin, PIN_HIGH);
+        }
         else
+        {
             rt_pin_write(device->cs_pin, PIN_LOW);
+        }
     }
 
     LOG_D("%s transfer prepare and start", spi_drv->config->bus_name);
@@ -344,7 +348,7 @@ static rt_ssize_t spixfer(struct rt_spi_device *device, struct rt_spi_message *m
         if ((spi_drv->spi_dma_flag & SPI_USING_TX_DMA_FLAG) && (send_length >= DMA_TRANS_MIN_LEN))
         {
 #if defined(SOC_SERIES_STM32H7) || defined(SOC_SERIES_STM32F7)
-            if (RT_IS_ALIGN((rt_uint32_t)send_buf, 32)) /* aligned with 32 bytes? */
+            if (RT_IS_ALIGN((rt_uint32_t)send_buf, 32) && send_buf != RT_NULL) /* aligned with 32 bytes? */
             {
                 p_txrx_buffer = (rt_uint32_t *)send_buf; /* send_buf aligns with 32 bytes, no more operations */
             }
@@ -357,7 +361,7 @@ static rt_ssize_t spixfer(struct rt_spi_device *device, struct rt_spi_message *m
             }
             rt_hw_cpu_dcache_ops(RT_HW_CACHE_FLUSH, dma_aligned_buffer, send_length);
 #else
-            if (RT_IS_ALIGN((rt_uint32_t)send_buf, 4)) /* aligned with 4 bytes? */
+            if (RT_IS_ALIGN((rt_uint32_t)send_buf, 4) && send_buf != RT_NULL) /* aligned with 4 bytes? */
             {
                 p_txrx_buffer = (rt_uint32_t *)send_buf; /* send_buf aligns with 4 bytes, no more operations */
             }