USB: ftdi_sio: optimise chars_in_buffer

No need to check hardware buffers when we know that the software buffers are non-empty. Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
git-mirror · Oct 30, 2012 · 8da636d · 8da636d
1 parent 755b604
commit 8da636d
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
@@ -2098,6 +2098,8 @@ static int ftdi_chars_in_buffer(struct tty_struct *tty)
 	int ret;
 
 	chars = usb_serial_generic_chars_in_buffer(tty);
+	if (chars)
+		return chars;
 
 	/* Check hardware buffer */
 	switch (priv->chip_type) {