[PATCH 5.16 004/186] ASoC: rt5682s: do not block workqueue if card is unbound

From: Greg Kroah-Hartman
Date: Mon Mar 07 2022 - 05:21:28 EST


From: Kai Vehmanen <kai.vehmanen@xxxxxxxxxxxxxxx>

[ Upstream commit d7b530fdc45e75a54914a194c4becd9672a4e24f ]

The current rt5682s_jack_detect_handler() assumes the component
and card will always show up and implements an infinite usleep
loop waiting for them to show up.

This does not hold true if a codec interrupt (or other
event) occurs when the card is unbound. The codec driver's
remove or shutdown functions cannot cancel the workqueue due
to the wait loop. As a result, code can either end up blocking
the workqueue, or hit a kernel oops when the card is freed.

Fix the issue by rescheduling the jack detect handler in
case the card is not ready. In case card never shows up,
the shutdown/remove/suspend calls can now cancel the detect
task.

Signed-off-by: Kai Vehmanen <kai.vehmanen@xxxxxxxxxxxxxxx>
Reviewed-by: Bard Liao <yung-chuan.liao@xxxxxxxxxxxxxxx>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@xxxxxxxxxxxxxxx>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@xxxxxxxxxxxxxxx>
Reviewed-by: Shuming Fan <shumingf@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220207153000.3452802-1-kai.vehmanen@xxxxxxxxxxxxxxx
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
sound/soc/codecs/rt5682s.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/sound/soc/codecs/rt5682s.c b/sound/soc/codecs/rt5682s.c
index d49a4f68566d2..d79b548d23fa4 100644
--- a/sound/soc/codecs/rt5682s.c
+++ b/sound/soc/codecs/rt5682s.c
@@ -824,11 +824,13 @@ static void rt5682s_jack_detect_handler(struct work_struct *work)
container_of(work, struct rt5682s_priv, jack_detect_work.work);
int val, btn_type;

- while (!rt5682s->component)
- usleep_range(10000, 15000);
-
- while (!rt5682s->component->card->instantiated)
- usleep_range(10000, 15000);
+ if (!rt5682s->component || !rt5682s->component->card ||
+ !rt5682s->component->card->instantiated) {
+ /* card not yet ready, try later */
+ mod_delayed_work(system_power_efficient_wq,
+ &rt5682s->jack_detect_work, msecs_to_jiffies(15));
+ return;
+ }

mutex_lock(&rt5682s->jdet_mutex);
mutex_lock(&rt5682s->calibrate_mutex);
--
2.34.1