ASoC: codecs: pcm3168a: Fix and updates for power management

Cezary Rojewski <cezary.rojewski@intel.com> says:

Set of changes composed of one fix and two improvements.

The fix leads the series and addresses "unbalanced disables" coming from
the regulator core during S4 (hibernation) scenario.

The SLEEP_PM_OPS are unset for the driver.  Hibernation (S4) causes no
resume (skipped thanks to smart_suspend=true) yet still performs the
suspend sequence unconditionally, see device_complete() in
drivers/base/power/main.c.  In essence, we end up with double suspend
(double disable) and thus the warning.  Exemplary stack:

unbalanced disables for regulator-dummy
WARNING: drivers/regulator/core.c:3244 at _regulator_disable+0x161/0x270, CPU#6: kworker/u64:2/120
(...)
Workqueue: pm pm_runtime_work
RIP: 0010:_regulator_disable+0x161/0x270
(...)
Call Trace:
  <TASK>
  regulator_bulk_disable+0xe4/0x220
  ? __pfx_regulator_bulk_disable+0x10/0x10
  ? pick_next_task_fair+0x36f/0x11f0
  ? __pfx_regmap_unlock_mutex+0x10/0x10
  ? regmap_unlock_mutex+0xe/0x20
  pcm3168a_rt_suspend+0x57/0x90 [snd_soc_pcm3168a]
  ? __pfx_pcm3168a_rt_suspend+0x10/0x10 [snd_soc_pcm3168a]
  __rpm_callback+0x69/0x200
  ? __pfx_pcm3168a_rt_suspend+0x10/0x10 [snd_soc_pcm3168a]
  rpm_callback+0xbc/0xd0
  rpm_suspend+0x225/0x960
  ? __pfx_rpm_suspend+0x10/0x10
  ? __kasan_check_write+0x14/0x20
  ? _raw_spin_lock_irq+0x8d/0xe0
  ? __pfx__raw_spin_lock_irq+0x10/0x10
  ? pwq_dec_nr_in_flight+0x63/0x4f0
  pm_runtime_work+0xd0/0xf0

In regard to the improvements, both aim to drop redundant operations.
One targets pm_runtime_idle() - no need to fire it manually,
device-driver core will do that for us - while the second replaces
preprocessor directive with pm_runtime_status_suspended() check.
No !CONFIG_PM dependency equals better code coverege with default
kconfigs.

Link: https://patch.msgid.link/20260525201801.1336936-1-cezary.rojewski@intel.com

1 files changed, 8 insertions, 14 deletions

diff --git a/sound/soc/codecs/pcm3168a.c b/sound/soc/codecs/pcm3168a.c
index c8617a488b11..4503f2f0724e 100644
--- a/sound/soc/codecs/pcm3168a.c
+++ b/sound/soc/codecs/pcm3168a.c
@@ -799,7 +799,6 @@ int pcm3168a_probe(struct device *dev, struct regmap *regmap)
 
 	pm_runtime_set_active(dev);
 	pm_runtime_enable(dev);
-	pm_runtime_idle(dev);
 
 	memcpy(pcm3168a->dai_drv, pcm3168a_dais, sizeof(pcm3168a->dai_drv));
 	ret = devm_snd_soc_register_component(dev, &pcm3168a_driver,
@@ -822,15 +821,6 @@ err_clk:
 }
 EXPORT_SYMBOL_GPL(pcm3168a_probe);
 
-static void pcm3168a_disable(struct device *dev)
-{
-	struct pcm3168a_priv *pcm3168a = dev_get_drvdata(dev);
-
-	regulator_bulk_disable(ARRAY_SIZE(pcm3168a->supplies),
-			       pcm3168a->supplies);
-	clk_disable_unprepare(pcm3168a->scki);
-}
-
 void pcm3168a_remove(struct device *dev)
 {
 	struct pcm3168a_priv *pcm3168a = dev_get_drvdata(dev);
@@ -842,10 +832,12 @@ void pcm3168a_remove(struct device *dev)
 	 * The asserted level of GPIO_ACTIVE_LOW is LOW.
 	 */
 	gpiod_set_value_cansleep(pcm3168a->gpio_rst, 1);
+
 	pm_runtime_disable(dev);
-#ifndef CONFIG_PM
-	pcm3168a_disable(dev);
-#endif
+	if (!pm_runtime_status_suspended(dev)) {
+		regulator_bulk_disable(ARRAY_SIZE(pcm3168a->supplies), pcm3168a->supplies);
+		clk_disable_unprepare(pcm3168a->scki);
+	}
 }
 EXPORT_SYMBOL_GPL(pcm3168a_remove);
 
@@ -900,13 +892,15 @@ static int pcm3168a_rt_suspend(struct device *dev)
 
 	regcache_cache_only(pcm3168a->regmap, true);
 
-	pcm3168a_disable(dev);
+	regulator_bulk_disable(ARRAY_SIZE(pcm3168a->supplies), pcm3168a->supplies);
+	clk_disable_unprepare(pcm3168a->scki);
 
 	return 0;
 }
 
 EXPORT_GPL_DEV_PM_OPS(pcm3168a_pm_ops) = {
 	RUNTIME_PM_OPS(pcm3168a_rt_suspend, pcm3168a_rt_resume, NULL)
+	SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume)
 };
 
 MODULE_DESCRIPTION("PCM3168A codec driver");