1 files changed, 21 insertions, 11 deletions

diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c
index 8d7b0847109b..95aa5233726c 100644
--- a/drivers/usb/serial/ch341.c
+++ b/drivers/usb/serial/ch341.c
@@ -113,6 +113,8 @@ static int ch341_control_out(struct usb_device *dev, u8 request,
         r = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), request,
                             USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
                             value, index, NULL, 0, DEFAULT_TIMEOUT);
+        if (r < 0)
+                dev_err(&dev->dev, "failed to send control message: %d\n", r);
 
         return r;
 }
@@ -130,7 +132,20 @@ static int ch341_control_in(struct usb_device *dev,
         r = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), request,
                             USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
                             value, index, buf, bufsize, DEFAULT_TIMEOUT);
-        return r;
+        if (r < bufsize) {
+                if (r >= 0) {
+                        dev_err(&dev->dev,
+                                "short control message received (%d < %u)\n",
+                                r, bufsize);
+                        r = -EIO;
+                }
+
+                dev_err(&dev->dev, "failed to receive control message: %d\n",
+                        r);
+                return r;
+        }
+
+        return 0;
 }
 
 static int ch341_set_baudrate_lcr(struct usb_device *dev,
@@ -181,9 +196,9 @@ static int ch341_set_handshake(struct usb_device *dev, u8 control)
 
 static int ch341_get_status(struct usb_device *dev, struct ch341_private *priv)
 {
+        const unsigned int size = 2;
         char *buffer;
         int r;
-        const unsigned size = 8;
         unsigned long flags;
 
         buffer = kmalloc(size, GFP_KERNEL);
@@ -194,14 +209,9 @@ static int ch341_get_status(struct usb_device *dev, struct ch341_private *priv)
         if (r < 0)
                 goto out;
 
-        /* setup the private status if available */
-        if (r == 2) {
-                r = 0;
-                spin_lock_irqsave(&priv->lock, flags);
-                priv->line_status = (~(*buffer)) & CH341_BITS_MODEM_STAT;
-                spin_unlock_irqrestore(&priv->lock, flags);
-        } else
-                r = -EPROTO;
+        spin_lock_irqsave(&priv->lock, flags);
+        priv->line_status = (~(*buffer)) & CH341_BITS_MODEM_STAT;
+        spin_unlock_irqrestore(&priv->lock, flags);
 
 out:    kfree(buffer);
         return r;
@@ -211,9 +221,9 @@ out:	kfree(buffer);
 
 static int ch341_configure(struct usb_device *dev, struct ch341_private *priv)
 {
+        const unsigned int size = 2;
         char *buffer;
         int r;
-        const unsigned size = 8;
 
         buffer = kmalloc(size, GFP_KERNEL);
         if (!buffer)