diff --git a/bsp/stm32/libraries/HAL_Drivers/drivers/drv_usart_v2.c b/bsp/stm32/libraries/HAL_Drivers/drivers/drv_usart_v2.c
index 225180d229d..b6c31454027 100644
--- a/bsp/stm32/libraries/HAL_Drivers/drivers/drv_usart_v2.c
+++ b/bsp/stm32/libraries/HAL_Drivers/drivers/drv_usart_v2.c
@@ -390,6 +390,10 @@ static rt_ssize_t stm32_transmit(struct rt_serial_device     *serial,
 
     if (uart->uart_dma_flag & RT_DEVICE_FLAG_DMA_TX)
     {
+#if defined (__DCACHE_PRESENT) && (__DCACHE_PRESENT == 1U)
+        struct rt_serial_tx_fifo *tx_fifo = (struct rt_serial_tx_fifo *) serial->serial_tx;
+        SCB_CleanDCache_by_Addr((uint32_t *)tx_fifo->rb.buffer_ptr, tx_fifo->rb.buffer_size);
+#endif    
         HAL_UART_Transmit_DMA(&uart->handle, buf, size);
         return size;
     }
diff --git a/components/drivers/include/drivers/dev_serial_v2.h b/components/drivers/include/drivers/dev_serial_v2.h
index 0bdc51b7baf..0624fa534c6 100644
--- a/components/drivers/include/drivers/dev_serial_v2.h
+++ b/components/drivers/include/drivers/dev_serial_v2.h
@@ -253,7 +253,7 @@ struct rt_serial_rx_fifo
     rt_uint16_t rx_cpt_index;
 
     /* software fifo */
-    rt_uint8_t buffer[];
+    rt_align(32) rt_uint8_t buffer[];
 };
 
 /**
@@ -271,7 +271,7 @@ struct rt_serial_tx_fifo
     struct rt_completion tx_cpt;
 
     /* software fifo */
-    rt_uint8_t buffer[];
+    rt_align(32) rt_uint8_t buffer[];
 };
 
 /**