From: Johan Hovold <jhovold@gmail.com>
Date: Mon, 29 Oct 2012 09:56:27 +0000 (+0100)
Subject: USB: ftdi_sio: optimise chars_in_buffer
X-Git-Tag: upstream/snapshot3+hdmi~6133^2~81
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=8da636d9b5f3af354458f5b7eadaf51f23017fdc;p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git

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 @@ 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) {