[SRU][B/B-OEM/C][PATCH 1/1] ALSA: hda - Enforces runtime_resume after S3 and S4 for each codec

[Hui Wang]

BugLink: http://bugs.launchpad.net/bugs/1820930

Recently we found the audio jack detection stop working after suspend
on many machines with Realtek codec. Sometimes the audio selection
dialogue didn't show up after users plugged headhphone/headset into
the headset jack, sometimes after uses plugged headphone/headset, then
click the sound icon on the upper-right corner of gnome-desktop, it
also showed the speaker rather than the headphone.

The root cause is that before suspend, the codec already call the
runtime_suspend since this codec is not used by any apps, then in
resume, it will not call runtime_resume for this codec. But for some
realtek codec (so far, alc236, alc255 and alc891) with the specific
BIOS, if it doesn't run runtime_resume after suspend, all codec
functions including jack detection stop working anymore.

This problem existed for a long time, but it was not exposed, that is
because when problem happens, if users play sound or open
sound-setting to check audio device, this will trigger calling to
runtime_resume (via snd_hda_power_up), then the codec starts working
again before users notice this problem.

Since we don't know how many codec and BIOS combinations have this
problem, to fix it, let the driver call runtime_resume for all codecs
in pm_resume, maybe for some codecs, this is not needed, but it is
harmless. After a codec is runtime resumed, if it is not used by any
apps, it will be runtime suspended soon and furthermore we don't run
suspend frequently, this change will not add much power consumption.

Fixes: cc72da7d4d06 ("ALSA: hda - Use standard runtime PM for codec power-save control")
Signed-off-by: Hui Wang <hui.wang at canonical.com>
Signed-off-by: Takashi Iwai <tiwai at suse.de>
(backported from commit b5a236c175b0d984552a5f7c9d35141024c2b261
git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound.git)
Signed-off-by: Hui Wang <hui.wang at canonical.com>
---
 sound/pci/hda/hda_codec.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index 39990fe4dee2..0444dba65d63 100644
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -2933,10 +2933,26 @@ static int hda_codec_runtime_resume(struct device *dev)
 }
 #endif /* CONFIG_PM */
 
+#ifdef CONFIG_PM_SLEEP
+static int hda_codec_force_resume(struct device *dev)
+{
+       int ret;
+
+       /* The get/put pair below enforces the runtime resume even if the
+        * device hasn't been used at suspend time.  This trick is needed to
+        * update the jack state change during the sleep.
+        */
+       pm_runtime_get_noresume(dev);
+       ret = pm_runtime_force_resume(dev);
+       pm_runtime_put(dev);
+       return ret;
+}
+#endif /* CONFIG_PM_SLEEP */
+
 /* referred in hda_bind.c */
 const struct dev_pm_ops hda_codec_driver_pm = {
 	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
-				pm_runtime_force_resume)
+				hda_codec_force_resume)
 	SET_RUNTIME_PM_OPS(hda_codec_runtime_suspend, hda_codec_runtime_resume,
 			   NULL)
 };
-- 
2.17.1