From 77b1e2fbbdfa0ee5cdf6c928b711493a3738468e Mon Sep 17 00:00:00 2001 From: Andreas Oberritter Date: Thu, 4 Aug 2011 12:33:15 -0300 Subject: [PATCH] [media] DVB: dvb_frontend: update locking in dvb_frontend_{add, get_event} - fepriv->parameters_out isn't protected by events->mtx, so move the call to fe->ops.get_frontend out of the locked area. - move the assignment of e->status into the locked area. - use direct assignment instead of memcpy. - use mutex_lock instead of mutex_lock_interruptible, because all code paths protected by this mutex won't block. Signed-off-by: Andreas Oberritter Signed-off-by: Mauro Carvalho Chehab --- drivers/media/dvb/dvb-core/dvb_frontend.c | 24 +++++++---------------- 1 file changed, 7 insertions(+), 17 deletions(-) diff --git a/drivers/media/dvb/dvb-core/dvb_frontend.c b/drivers/media/dvb/dvb-core/dvb_frontend.c index 41023111220..d02c32e754f 100644 --- a/drivers/media/dvb/dvb-core/dvb_frontend.c +++ b/drivers/media/dvb/dvb-core/dvb_frontend.c @@ -149,30 +149,25 @@ static void dvb_frontend_add_event(struct dvb_frontend *fe, fe_status_t status) dprintk ("%s\n", __func__); - if (mutex_lock_interruptible (&events->mtx)) - return; + if ((status & FE_HAS_LOCK) && fe->ops.get_frontend) + fe->ops.get_frontend(fe, &fepriv->parameters_out); - wp = (events->eventw + 1) % MAX_EVENT; + mutex_lock(&events->mtx); + wp = (events->eventw + 1) % MAX_EVENT; if (wp == events->eventr) { events->overflow = 1; events->eventr = (events->eventr + 1) % MAX_EVENT; } e = &events->events[events->eventw]; - - if (status & FE_HAS_LOCK) - if (fe->ops.get_frontend) - fe->ops.get_frontend(fe, &fepriv->parameters_out); - + e->status = status; e->parameters = fepriv->parameters_out; events->eventw = wp; mutex_unlock(&events->mtx); - e->status = status; - wake_up_interruptible (&events->wait_queue); } @@ -207,14 +202,9 @@ static int dvb_frontend_get_event(struct dvb_frontend *fe, return ret; } - if (mutex_lock_interruptible (&events->mtx)) - return -ERESTARTSYS; - - memcpy (event, &events->events[events->eventr], - sizeof(struct dvb_frontend_event)); - + mutex_lock(&events->mtx); + *event = events->events[events->eventr]; events->eventr = (events->eventr + 1) % MAX_EVENT; - mutex_unlock(&events->mtx); return 0; -- 2.20.1