[PATCH] media: em28xx - fix i2c_xfer to return -ENODEV when dev is removed

From: Shuah Khan
Date: Fri Jul 11 2014 - 17:26:06 EST

In em28xx usb disconnect code path, some dvb fe and tuner drivers
attempt i2c transfers from their release interfaces. When device
is removed, return -ENODEV instead of attempting to transfer data
over i2c.

Signed-off-by: Shuah Khan <shuah.kh@xxxxxxxxxxx>
drivers/media/usb/em28xx/em28xx-i2c.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/media/usb/em28xx/em28xx-i2c.c b/drivers/media/usb/em28xx/em28xx-i2c.c
index b58d4eb..1048c1a 100644
--- a/drivers/media/usb/em28xx/em28xx-i2c.c
+++ b/drivers/media/usb/em28xx/em28xx-i2c.c
@@ -501,6 +501,12 @@ static int em28xx_i2c_xfer(struct i2c_adapter *i2c_adap,
int addr, rc, i;
u8 reg;

+ /* prevent i2c xfer attempts after device is disconnected
+ some fe's try to do i2c writes/reads from their release
+ interfaces when called in disconnect path */
+ if (dev->disconnected)
+ return -ENODEV;
rc = rt_mutex_trylock(&dev->i2c_bus_lock);
if (rc < 0)
return rc;

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