Commit fe8b81fd authored by Nicolas Dufresne's avatar Nicolas Dufresne Committed by Mauro Carvalho Chehab
Browse files

media: cedrus: Fix watchdog race condition 



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: 7c38a551 ("media: cedrus: Add watchdog for job completion")
Signed-off-by: default avatarNicolas Dufresne <nicolas.dufresne@collabora.com>
Reviewed-by: default avatarPaul Kocialkowski <paul.kocialkowski@bootlin.com>
Signed-off-by: default avatarHans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@kernel.org>
parent 2801f6f3

drivers/staging/media/sunxi/cedrus/cedrus_dec.c

+2 −2
Original line number Diff line number Diff line
@@ -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,