[PATCH 5.16 006/186] ASoC: rt5682: do not block workqueue if card is unbound

From: Greg Kroah-Hartman
Date: Mon Mar 07 2022 - 05:22:55 EST


From: Kai Vehmanen <kai.vehmanen@xxxxxxxxxxxxxxx>

[ Upstream commit 4c33de0673ced9c7c37b3bbd9bfe0fda72340b2a ]

The current rt5682_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/20220207153000.3452802-3-kai.vehmanen@xxxxxxxxxxxxxxx
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
sound/soc/codecs/rt5682.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/sound/soc/codecs/rt5682.c b/sound/soc/codecs/rt5682.c
index 7e6e2f26accd0..e3643ae6de66d 100644
--- a/sound/soc/codecs/rt5682.c
+++ b/sound/soc/codecs/rt5682.c
@@ -1092,11 +1092,13 @@ void rt5682_jack_detect_handler(struct work_struct *work)
struct snd_soc_dapm_context *dapm;
int val, btn_type;

- while (!rt5682->component)
- usleep_range(10000, 15000);
-
- while (!rt5682->component->card->instantiated)
- usleep_range(10000, 15000);
+ if (!rt5682->component || !rt5682->component->card ||
+ !rt5682->component->card->instantiated) {
+ /* card not yet ready, try later */
+ mod_delayed_work(system_power_efficient_wq,
+ &rt5682->jack_detect_work, msecs_to_jiffies(15));
+ return;
+ }

dapm = snd_soc_component_get_dapm(rt5682->component);

--
2.34.1