USB: ftdi_sio: optimise chars_in_buffer
authorJohan Hovold <jhovold@gmail.com>
Mon, 29 Oct 2012 09:56:27 +0000 (10:56 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 30 Oct 2012 20:19:32 +0000 (13:19 -0700)
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>
drivers/usb/serial/ftdi_sio.c

index 9fe3a2e965adebbfba6074d21f2a253899f33aaf..b8bc9d0cb127f8c467698a9bc83a0602e66a8d8d 100644 (file)
@@ -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) {