From: Hans Verkuil Date: Tue, 8 Sep 2020 10:02:53 +0000 (+0200) Subject: media: cec-adap.c: don't use flush_scheduled_work() X-Git-Tag: v5.8.13~12 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=464b2d4cba99912810f13bdae1dd725140f8b964;p=thirdparty%2Fkernel%2Fstable.git media: cec-adap.c: don't use flush_scheduled_work() commit 288eceb0858323d66bff03cf386630a797b248ad upstream. For some inexplicable reason I decided to call flush_scheduled_work() instead of cancel_delayed_work_sync(). The problem with that is that flush_scheduled_work() waits for *all* queued scheduled work to be completed instead of just the work itself. This can cause a deadlock if a CEC driver also schedules work that takes the same lock. See the comments for flush_scheduled_work() in linux/workqueue.h. This is exactly what has been observed a few times. This patch simply replaces flush_scheduled_work() by cancel_delayed_work_sync(). Signed-off-by: Hans Verkuil Cc: # for v5.8 and up Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/media/cec/core/cec-adap.c b/drivers/media/cec/core/cec-adap.c index 6a04d19a96b2e..accc893243295 100644 --- a/drivers/media/cec/core/cec-adap.c +++ b/drivers/media/cec/core/cec-adap.c @@ -1199,7 +1199,7 @@ void cec_received_msg_ts(struct cec_adapter *adap, /* Cancel the pending timeout work */ if (!cancel_delayed_work(&data->work)) { mutex_unlock(&adap->lock); - flush_scheduled_work(); + cancel_delayed_work_sync(&data->work); mutex_lock(&adap->lock); } /*