[utest][driver][serial_v2] 优化flush判断逻辑

Author: Ryan-CW-Code

components/drivers/serial/utest/Kconfig

@@ -16,6 +16,10 @@ menu "Serial Test"
             string "Device Name for Serial Test"
             default "uart2"
 
+        config RT_SERIAL_TC_DEVICE_USING_TX_DMA
+            bool "Selected serial device is using TX DMA"
+            default n
+
         config RT_SERIAL_TC_RXBUF_SIZE
             int "RX Buffer Size for Serial Test"
             default 128

components/drivers/serial/utest/v2/uart_flush_txb.c

@@ -64,7 +64,8 @@ static rt_err_t test_item(rt_uint8_t *uart_write_buffer, rt_uint32_t send_size)
     rt_device_control(&serial->parent, RT_SERIAL_CTRL_TX_FLUSH, RT_NULL);
     tick_diff = rt_tick_get() - old_tick;
 
-    if (tick_diff < expect_time || tick_diff > (expect_time + 10))
+    rt_uint32_t lower_bound = (expect_time > 2) ? (expect_time - 2) : 0;
+    if (tick_diff < lower_bound || tick_diff > (expect_time + 10))
     {
         LOG_E("send_size [%4d], time required for TXB mode transmission to complete [%3d], expect_time [%3d]", send_size, tick_diff, expect_time);
         return -RT_ERROR;

components/drivers/serial/utest/v2/uart_flush_txnb.c

@@ -64,7 +64,8 @@ static rt_err_t test_item(rt_uint8_t *uart_write_buffer, rt_uint32_t send_size)
     rt_device_control(&serial->parent, RT_SERIAL_CTRL_TX_FLUSH, RT_NULL);
     tick_diff = rt_tick_get() - old_tick;
 
-    if (tick_diff < expect_time || tick_diff > (expect_time + 10))
+    rt_uint32_t lower_bound = (expect_time > 2) ? (expect_time - 2) : 0;
+    if (tick_diff < lower_bound || tick_diff > (expect_time + 10))
     {
         LOG_E("send_size [%4d], time required for TXNB mode transmission to complete [%3d], expect_time [%3d]", send_size, tick_diff, expect_time);
         return -RT_ERROR;

components/drivers/serial/utest/v2/uart_timeout_txb.c

@@ -14,7 +14,7 @@
 #include <stdlib.h>
 
 #ifdef RT_UTEST_SERIAL_V2
-#ifndef BSP_UART2_TX_USING_DMA
+#ifndef RT_SERIAL_TC_DEVICE_USING_TX_DMA
 
 static struct rt_serial_device *serial;