[PATCH v3 1/4] ALSA: hda/realtek: Power up codec when setting LED via COEF and GPIO

[Kai-Heng Feng]

System takes a very long time to suspend after commit 215a22ed31a1
("ALSA: hda: Refactor codec PM to use direct-complete optimization"):
[   90.065964] PM: suspend entry (s2idle)
[   90.067337] Filesystems sync: 0.001 seconds
[   90.185758] Freezing user space processes ... (elapsed 0.002 seconds) done.
[   90.188713] OOM killer disabled.
[   90.188714] Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done.
[   90.190024] printk: Suspending console(s) (use no_console_suspend to debug)
[   90.904912] intel_pch_thermal 0000:00:12.0: CPU-PCH is cool [49C], continue to suspend
[  321.262505] snd_hda_codec_realtek ehdaudio0D0: Unable to sync register 0x2b8000. -5
[  328.426919] snd_hda_codec_realtek ehdaudio0D0: Unable to sync register 0x2b8000. -5
[  329.490933] ACPI: EC: interrupt blocked

That commit keeps the codec suspended during the system suspend. However,
led_suspend() for mute and micmute led writes codec register, triggers
a pending wake up. The wakeup is then handled in __device_suspend() by
the following:
- pm_runtime_disable() to handle the wakeup event.
- device is no longer is suspended state, direct-complete isn't taken.
- pm_runtime_enable() to balance disable_depth.

if (dev->power.direct_complete) {
	if (pm_runtime_status_suspended(dev)) {
		pm_runtime_disable(dev);
		if (pm_runtime_status_suspended(dev)) {
			pm_dev_dbg(dev, state, "direct-complete ");
			goto Complete;
		}

		pm_runtime_enable(dev);
	}
	dev->power.direct_complete = false;
}

Since direct-complete doens't apply anymore, the codec's system suspend
routine is used.

This doesn't play well with SOF driver. When its runtime resume is
called for system suspend, hda_codec_jack_check() schedules
jackpoll_work which uses snd_hdac_is_power_on() to check whether codec
is suspended. Because of the previous pm_runtime_enable(),
snd_hdac_is_power_on() returns false and jackpoll continues to run, and
snd_hda_power_up_pm() cannot power up an already suspended codec in
multiple attempts, causes the long delay on system suspend.

When direct-complete path is taken, snd_hdac_is_power_on() returns true
and hda_jackpoll_work() is skipped by accident. This is still not
correct, and it will be addressed by later patch.

Explicitly runtime resume codec on setting LED to solve the issue.

Fixes: 215a22ed31a1 ("ALSA: hda: Refactor codec PM to use direct-complete optimization")
---
v3:
 New patch.

 sound/pci/hda/patch_realtek.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/sound/pci/hda/patch_realtek.c b/sound/pci/hda/patch_realtek.c
index 3c1d2a3fb1a4..304a7bc89fcd 100644
--- a/sound/pci/hda/patch_realtek.c
+++ b/sound/pci/hda/patch_realtek.c
@@ -4164,7 +4164,10 @@ static void alc_update_gpio_led(struct hda_codec *codec, unsigned int mask,
 {
 	if (polarity)
 		enabled = !enabled;
+	/* temporarily power up/down for setting GPIO */
+	snd_hda_power_up_pm(codec);
 	alc_update_gpio_data(codec, mask, !enabled); /* muted -> LED on */
+	snd_hda_power_down_pm(codec);
 }
 
 /* turn on/off mute LED via GPIO per vmaster hook */
@@ -4287,8 +4290,10 @@ static void alc_update_coef_led(struct hda_codec *codec,
 	if (polarity)
 		on = !on;
 	/* temporarily power up/down for setting COEF bit */
+	snd_hda_power_up_pm(codec);
 	alc_update_coef_idx(codec, led->idx, led->mask,
 			    on ? led->on : led->off);
+	snd_hda_power_down_pm(codec);
 }
 
 /* update mute-LED according to the speaker mute state via COEF bit */
-- 
2.29.2