From 77daf413be26940398464735a62065b3fde49a79 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E5=91=A8=E4=BC=A0=E7=A6=8F?=
 <46174387+zhouchuanfu@users.noreply.github.com>
Date: Thu, 16 May 2019 12:37:25 +0800
Subject: [PATCH] Update drv_usart.c
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添加函数说明
---
 bsp/stm32/libraries/HAL_Drivers/drv_usart.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/bsp/stm32/libraries/HAL_Drivers/drv_usart.c b/bsp/stm32/libraries/HAL_Drivers/drv_usart.c
index 8d75b4dd8f..68133457b4 100644
--- a/bsp/stm32/libraries/HAL_Drivers/drv_usart.c
+++ b/bsp/stm32/libraries/HAL_Drivers/drv_usart.c
@@ -631,6 +631,14 @@ void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
     uart = (struct stm32_uart *)huart;
     dma_isr(&uart->serial);
 }
+
+/**
+  * @brief  Rx Half transfer completed callback
+  * @param  huart: UART handle
+  * @note   This example shows a simple way to report end of DMA Rx Half transfer, 
+  *         and you can add your own implementation.
+  * @retval None
+  */
 void HAL_UART_RxHalfCpltCallback(UART_HandleTypeDef *huart)
 {
     struct stm32_uart *uart;