From: Nicolas Dufresne nicolas.dufresne@collabora.com
commit fe8b81fde69acfcbb5af9e85328e5b9549999fdb upstream.
The watchdog needs to be scheduled before we trigger the decode operation, otherwise there is a risk that the decoder IRQ will be called before we have schedule the watchdog. As a side effect, the watchdog would never be cancelled and its function would be called at an inappropriate time.
This was observed while running Fluster with GStreamer as a backend. Some programming error would cause the decoder IRQ to be call very quickly after the trigger. Later calls into the driver would deadlock due to the unbalanced state.
Cc: stable@vger.kernel.org Fixes: 7c38a551bda1 ("media: cedrus: Add watchdog for job completion") Signed-off-by: Nicolas Dufresne nicolas.dufresne@collabora.com Reviewed-by: Paul Kocialkowski paul.kocialkowski@bootlin.com Signed-off-by: Hans Verkuil hverkuil-cisco@xs4all.nl Signed-off-by: Mauro Carvalho Chehab mchehab@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/staging/media/sunxi/cedrus/cedrus_dec.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/staging/media/sunxi/cedrus/cedrus_dec.c +++ b/drivers/staging/media/sunxi/cedrus/cedrus_dec.c @@ -106,11 +106,11 @@ void cedrus_device_run(void *priv)
/* Trigger decoding if setup went well, bail out otherwise. */ if (!error) { - dev->dec_ops[ctx->current_codec]->trigger(ctx); - /* Start the watchdog timer. */ schedule_delayed_work(&dev->watchdog_work, msecs_to_jiffies(2000)); + + dev->dec_ops[ctx->current_codec]->trigger(ctx); } else { v4l2_m2m_buf_done_and_job_finish(ctx->dev->m2m_dev, ctx->fh.m2m_ctx,