[PATCH] ALSA: hda: Fix crash due to jack poll in suspend

[PATCH] ALSA: hda: Fix crash due to jack poll in suspend

[Mohan Kumar]

With jackpoll_in_suspend flag set, there is a possibility that
jack poll worker thread will run even after system suspend was
completed. Any register access after system pm callback flow
will result in kernel crash as still jack poll worker thread
tries to access registers.

To fix the crash issue during system flow, cancel the jack poll
worker thread during system pm prepare callback and cancel the
worker thread at start of runtime suspend callback and re-schedule
at last to avoid any unwarranted access of register by worker thread
during suspend flow.

Signed-off-by: Mohan Kumar <mkumard@nvidia.com>
---
 sound/pci/hda/hda_codec.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index 7b2e62fa82d5..384426d7e9dd 100644
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -2940,8 +2940,7 @@ static int hda_codec_runtime_suspend(struct device *dev)
 	if (!codec->card)
 		return 0;
 
-	if (!codec->bus->jackpoll_in_suspend)
-		cancel_delayed_work_sync(&codec->jackpoll_work);
+	cancel_delayed_work_sync(&codec->jackpoll_work);
 
 	state = hda_call_codec_suspend(codec);
 	if (codec->link_down_at_suspend ||
@@ -2949,6 +2948,11 @@ static int hda_codec_runtime_suspend(struct device *dev)
 	     (state & AC_PWRST_CLK_STOP_OK)))
 		snd_hdac_codec_link_down(&codec->core);
 	snd_hda_codec_display_power(codec, false);
+
+	if (codec->bus->jackpoll_in_suspend &&
+		(dev->power.power_state.event != PM_EVENT_SUSPEND))
+		schedule_delayed_work(&codec->jackpoll_work,
+					codec->jackpoll_interval);
 	return 0;
 }
 
@@ -2972,6 +2976,9 @@ static int hda_codec_runtime_resume(struct device *dev)
 #ifdef CONFIG_PM_SLEEP
 static int hda_codec_pm_prepare(struct device *dev)
 {
+	struct hda_codec *codec = dev_to_hda_codec(dev);
+
+	cancel_delayed_work_sync(&codec->jackpoll_work);
 	dev->power.power_state = PMSG_SUSPEND;
 	return pm_runtime_suspended(dev);
 }
@@ -2991,9 +2998,6 @@ static void hda_codec_pm_complete(struct device *dev)
 
 static int hda_codec_pm_suspend(struct device *dev)
 {
-	struct hda_codec *codec = dev_to_hda_codec(dev);
-
-	cancel_delayed_work_sync(&codec->jackpoll_work);
 	dev->power.power_state = PMSG_SUSPEND;
 	return pm_runtime_force_suspend(dev);
 }
-- 
2.17.1