This is a note to let you know that I've just added the patch titled
media: cedrus: Fix watchdog race condition
to the 6.0-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
media-cedrus-fix-watchdog-race-condition.patch
and it can be found in the queue-6.0 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From fe8b81fde69acfcbb5af9e85328e5b9549999fdb Mon Sep 17 00:00:00 2001
From: Nicolas Dufresne <nicolas.dufresne@xxxxxxxxxxxxx>
Date: Thu, 18 Aug 2022 22:33:06 +0200
Subject: media: cedrus: Fix watchdog race condition
From: Nicolas Dufresne <nicolas.dufresne@xxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxx
Fixes: 7c38a551bda1 ("media: cedrus: Add watchdog for job completion")
Signed-off-by: Nicolas Dufresne <nicolas.dufresne@xxxxxxxxxxxxx>
Reviewed-by: Paul Kocialkowski <paul.kocialkowski@xxxxxxxxxxx>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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,
Patches currently in stable-queue which might be from nicolas.dufresne@xxxxxxxxxxxxx are
queue-6.0/media-cedrus-set-the-platform-driver-data-earlier.patch
queue-6.0/media-cedrus-fix-watchdog-race-condition.patch
queue-6.0/media-cedrus-fix-endless-loop-in-cedrus_h265_skip_bits.patch
