From 4ff5ed44f84aed6727ec226853a1c6b03c36db5e Mon Sep 17 00:00:00 2001 From: Devin Heitmueller Date: Wed, 11 Mar 2009 03:00:45 -0300 Subject: [PATCH] V4L/DVB (11069): au8522: add mutex protecting use of hybrid state Access using the hybrid state framework requires the list to be protected by a mutex. Thanks to Michael Krufky for reporting this during a code review. Signed-off-by: Devin Heitmueller Signed-off-by: Michael Krufky Signed-off-by: Mauro Carvalho Chehab --- drivers/media/dvb/frontends/au8522_dig.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/media/dvb/frontends/au8522_dig.c b/drivers/media/dvb/frontends/au8522_dig.c index b04346687c68..7e24b914dbe5 100644 --- a/drivers/media/dvb/frontends/au8522_dig.c +++ b/drivers/media/dvb/frontends/au8522_dig.c @@ -34,6 +34,7 @@ static int debug; /* Despite the name "hybrid_tuner", the framework works just as well for hybrid demodulators as well... */ static LIST_HEAD(hybrid_tuner_instance_list); +static DEFINE_MUTEX(au8522_list_mutex); #define dprintk(arg...) do { \ if (debug) \ @@ -795,15 +796,23 @@ static struct dvb_frontend_ops au8522_ops; int au8522_get_state(struct au8522_state **state, struct i2c_adapter *i2c, u8 client_address) { - return hybrid_tuner_request_state(struct au8522_state, (*state), - hybrid_tuner_instance_list, - i2c, client_address, "au8522"); + int ret; + + mutex_lock(&au8522_list_mutex); + ret = hybrid_tuner_request_state(struct au8522_state, (*state), + hybrid_tuner_instance_list, + i2c, client_address, "au8522"); + mutex_unlock(&au8522_list_mutex); + + return ret; } void au8522_release_state(struct au8522_state *state) { + mutex_lock(&au8522_list_mutex); if (state != NULL) hybrid_tuner_release_state(state); + mutex_unlock(&au8522_list_mutex); }