If release is part of frontend ops then it is called in the course of dvb_frontend_detach. The process also decrements the module usage count. The problem is if the lgdt3306a driver is reached via i2c_new_device, then when it is eventually destroyed remove is called, which further decrements the module usage count to negative. After this occurs the driver is in a bad state and no longer works. Also fixed by NULLing out the release callback is a double kfree of state, which introduces arbitrary oopses/GPF. This problem is only currently reachable via the em28xx driver. On disconnect of Hauppauge SoloHD before: lsmod | grep lgdt3306a lgdt3306a 28672 -1 i2c_mux 16384 1 lgdt3306a On disconnect of Hauppauge SoloHD after: lsmod | grep lgdt3306a lgdt3306a 28672 0 i2c_mux 16384 1 lgdt3306a Signed-off-by: Brad Love <brad@xxxxxxxxxxxxxxxx> --- drivers/media/dvb-frontends/lgdt3306a.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/media/dvb-frontends/lgdt3306a.c b/drivers/media/dvb-frontends/lgdt3306a.c index 6356815..d2477ed 100644 --- a/drivers/media/dvb-frontends/lgdt3306a.c +++ b/drivers/media/dvb-frontends/lgdt3306a.c @@ -2177,6 +2177,7 @@ static int lgdt3306a_probe(struct i2c_client *client, i2c_set_clientdata(client, fe->demodulator_priv); state = fe->demodulator_priv; + state->frontend.ops.release = NULL; /* create mux i2c adapter for tuner */ state->muxc = i2c_mux_alloc(client->adapter, &client->dev, -- 2.7.4
