staging: vt6656: Fix non zero logical return of, usb_control_msg

Starting with commit 59608cb1de1856
("staging: vt6656: clean function's error path in usbpipe.c")
the usb control functions have returned errors throughout driver
with only logical variable checking.

However, usb_control_msg return the amount of bytes transferred
this means that normal operation causes errors.

Correct the return function so only return zero when transfer
is successful.

Cc: stable <stable@vger.kernel.org> # v5.3+
Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Link: https://lore.kernel.org/r/08e88842-6f78-a2e3-a7a0-139fec960b2b@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/vt6656/usbpipe.c b/drivers/staging/vt6656/usbpipe.c
index d3304df6bd53de0a6db5c41f903cce5ee7561146..488ebd98773da6ae69480ea37c15478c97c2fa94 100644 (file)
--- a/drivers/staging/vt6656/usbpipe.c
+++ b/drivers/staging/vt6656/usbpipe.c
@@ -59,7 +59,9 @@ int vnt_control_out(struct vnt_private *priv, u8 request, u16 value,
 
        kfree(usb_buffer);
 
-       if (ret >= 0 && ret < (int)length)
+       if (ret == (int)length)
+               ret = 0;
+       else
                ret = -EIO;
 
 end_unlock:
@@ -103,7 +105,9 @@ int vnt_control_in(struct vnt_private *priv, u8 request, u16 value,
 
        kfree(usb_buffer);
 
-       if (ret >= 0 && ret < (int)length)
+       if (ret == (int)length)
+               ret = 0;
+       else
                ret = -EIO;
 
 end_unlock: