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>
diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index 9fe3a2e..b8bc9d0 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -2098,6 +2098,8 @@
int ret;
chars = usb_serial_generic_chars_in_buffer(tty);
+ if (chars)
+ return chars;
/* Check hardware buffer */
switch (priv->chip_type) {