From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Mon, 9 May 2016 08:22:55 +0000 (-0300)
Subject: em28xx-i2c: rt_mutex_trylock() returns zero on failure
X-Git-Tag: v4.7.7~61
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=58ae1d53c880ddac8f408d848c1f64760834c770;p=thirdparty%2Fkernel%2Fstable.git

em28xx-i2c: rt_mutex_trylock() returns zero on failure

commit e44c153b30c9a0580fc2b5a93f3c6d593def2278 upstream.

The code is checking for negative returns but it should be checking for
zero.

Fixes: aab3125c43d8 ('[media] em28xx: add support for registering multiple i2c buses')

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/media/usb/em28xx/em28xx-i2c.c b/drivers/media/usb/em28xx/em28xx-i2c.c
index a19b5c8b56ff7..1a9e1e556706c 100644
--- a/drivers/media/usb/em28xx/em28xx-i2c.c
+++ b/drivers/media/usb/em28xx/em28xx-i2c.c
@@ -507,9 +507,8 @@ static int em28xx_i2c_xfer(struct i2c_adapter *i2c_adap,
 	if (dev->disconnected)
 		return -ENODEV;
 
-	rc = rt_mutex_trylock(&dev->i2c_bus_lock);
-	if (rc < 0)
-		return rc;
+	if (!rt_mutex_trylock(&dev->i2c_bus_lock))
+		return -EAGAIN;
 
 	/* Switch I2C bus if needed */
 	if (bus != dev->cur_i2c_bus &&