From 979891763867433a92691c9eebfb0c6bb5ff2281 Mon Sep 17 00:00:00 2001
From: ChunfengMu <huahua932741850@qq.com>
Date: Wed, 31 Jan 2018 02:37:34 +0800
Subject: [PATCH] =?UTF-8?q?1:=E8=A7=A3=E5=86=B3=E4=B8=BB=E6=9C=BA=E7=AB=AF?=
 =?UTF-8?q?=E6=9C=AA=E6=89=93=E5=BC=80=E4=B8=B2=E5=8F=A3=E6=97=B6,?=
 =?UTF-8?q?=E8=AE=BE=E5=A4=87=E7=AB=AF=E5=BA=94=E7=94=A8=E7=A8=8B=E5=BA=8F?=
 =?UTF-8?q?dma=E6=A8=A1=E5=BC=8F=E4=B8=8B=E6=93=8D=E4=BD=9Cvcom=E5=8F=91?=
 =?UTF-8?q?=E9=80=81=E6=95=B0=E6=8D=AE=E6=97=B6,dataqueue=E6=9D=A1?=
 =?UTF-8?q?=E7=9B=AE=E6=B3=84=E6=BC=8F=E7=9A=84=E9=97=AE=E9=A2=98=E3=80=82?=
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---
 components/drivers/usb/usbdevice/class/cdc_vcom.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/components/drivers/usb/usbdevice/class/cdc_vcom.c b/components/drivers/usb/usbdevice/class/cdc_vcom.c
index 5188d98102..e1549e49a7 100644
--- a/components/drivers/usb/usbdevice/class/cdc_vcom.c
+++ b/components/drivers/usb/usbdevice/class/cdc_vcom.c
@@ -260,7 +260,7 @@ static rt_err_t _ep_in_handler(ufunction_t func, rt_size_t size)
 
     RT_DEBUG_LOG(RT_DEBUG_USB, ("_ep_in_handler %d\n", size));
     data = (struct vcom*)func->user_data;
-    if ((size != 0) && (size % CDC_MAX_PACKET_SIZE == 0))
+    if ((size != 0) && ((size % EP_MAXPACKET(data->ep_in)) == 0))
     {
         /* don't have data right now. Send a zero-length-packet to
          * terminate the transaction.
@@ -707,6 +707,8 @@ static rt_size_t _vcom_tx(struct rt_serial_device *serial, rt_uint8_t *buf, rt_s
                     level = rt_hw_interrupt_disable();
                     size += rt_ringbuffer_put_force(&data->tx_ringbuffer, (const rt_uint8_t *)&buf[size], ptr - size);
                     rt_hw_interrupt_enable(level);
+
+                    /* no data was be ignored */
                     if(size == ptr)
                     {
                         level = rt_hw_interrupt_disable();
@@ -722,6 +724,8 @@ static rt_size_t _vcom_tx(struct rt_serial_device *serial, rt_uint8_t *buf, rt_s
                         empty = 1;
                         break;
                     }
+
+                    /* ring buffer is full */
                     if(size == ptr)
                     {
                         empty = 1;
@@ -735,6 +739,7 @@ static rt_size_t _vcom_tx(struct rt_serial_device *serial, rt_uint8_t *buf, rt_s
                 }
             }
         }
+
         if(size < baksize && !empty)
         {
             level = rt_hw_interrupt_disable();
@@ -742,12 +747,17 @@ static rt_size_t _vcom_tx(struct rt_serial_device *serial, rt_uint8_t *buf, rt_s
             rt_hw_interrupt_enable(level);
         }
 
-
         if(size)
         {
             rt_event_send(&data->tx_event, CDC_TX_HAS_DATE);
         }
     }
+    else
+    {
+        /* recover dataqueue resources */
+        rt_hw_serial_isr(&data->serial,RT_SERIAL_EVENT_TX_DMADONE);
+    }
+
     return size;
 }
 static int _vcom_putc(struct rt_serial_device *serial, char c)