Commit c4c8dd6e authored by Takashi Iwai's avatar Takashi Iwai
Browse files

ALSA: hda: Skip controller resume if not needed 

The HD-audio controller does system-suspend and resume operations by
directly calling its helpers __azx_runtime_suspend() and
__azx_runtime_resume().  However, in general, we don't have to resume
always the device fully at the system resume; typically, if a device
has been runtime-suspended, we can leave it to runtime resume.

Usually for achieving this, the driver would call
pm_runtime_force_suspend() and pm_runtime_force_resume() pairs in the
system suspend and resume ops.  Unfortunately, this doesn't work for
the resume path in our case.  For handling the jack detection at the
system resume, a child codec device may need the (literally) forcibly
resume even if it's been runtime-suspended, and for that, the
controller device must be also resumed even if it's been suspended.

This patch is an attempt to improve the situation.  It replaces the
direct __azx_runtime_suspend()/_resume() calls with with
pm_runtime_force_suspend() and pm_runtime_force_resume() with a slight
trick as we've done for the codec side.  More exactly:

- azx_has_pm_runtime() check is dropped from azx_runtime_suspend() and
  azx_runtime_resume(), so that it can be properly executed from the
  system-suspend/resume path

- The WAKEEN handling depends on the card's power state now; it's set
  and cleared only for the runtime-suspend

- azx_resume() checks whether any codec may need the forcible resume
  beforehand.  If the forcible resume is required, it does temporary
  PM refcount up/down for actually triggering the runtime resume.

- A new helper function, hda_codec_need_resume(), is introduced for
  checking whether the codec needs a forcible runtime-resume, and the
  existing code is rewritten with that.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=207043
Link: https://lore.kernel.org/r/20200413082034.25166-6-tiwai@suse.de


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 9479e75f

include/sound/hda_codec.h

+5 −0
Original line number Diff line number Diff line
@@ -494,6 +494,11 @@ void snd_hda_update_power_acct(struct hda_codec *codec); 
static inline void snd_hda_set_power_save(struct hda_bus *bus, int delay) {}

#endif



static inline bool hda_codec_need_resume(struct hda_codec *codec)

{

	return !codec->relaxed_resume && codec->jacktbl.used;

}



#ifdef CONFIG_SND_HDA_PATCH_LOADER

/*

 * patch firmware

sound/pci/hda/hda_codec.c

+1 −1
Original line number Diff line number Diff line
@@ -2951,7 +2951,7 @@ static int hda_codec_runtime_resume(struct device *dev) 
static int hda_codec_force_resume(struct device *dev)

{

	struct hda_codec *codec = dev_to_hda_codec(dev);

	bool forced_resume = !codec->relaxed_resume && codec->jacktbl.used;

	bool forced_resume = hda_codec_need_resume(codec);

	int ret;



	/* The get/put pair below enforces the runtime resume even if the

sound/pci/hda/hda_intel.c

+27 −11
Original line number Diff line number Diff line
@@ -1027,7 +1027,7 @@ static int azx_suspend(struct device *dev) 
	chip = card->private_data;

	bus = azx_bus(chip);

	snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);

	__azx_runtime_suspend(chip);

	pm_runtime_force_suspend(dev);

	if (bus->irq >= 0) {

		free_irq(bus->irq, chip);

		bus->irq = -1;
@@ -1044,7 +1044,9 @@ static int azx_suspend(struct device *dev) 
static int azx_resume(struct device *dev)

{

	struct snd_card *card = dev_get_drvdata(dev);

	struct hda_codec *codec;

	struct azx *chip;

	bool forced_resume = false;



	if (!azx_is_pm_ready(card))

		return 0;
@@ -1055,7 +1057,20 @@ static int azx_resume(struct device *dev) 
			chip->msi = 0;

	if (azx_acquire_irq(chip, 1) < 0)

		return -EIO;

	__azx_runtime_resume(chip, false);



	/* check for the forced resume */

	list_for_each_codec(codec, &chip->bus) {

		if (hda_codec_need_resume(codec)) {

			forced_resume = true;

			break;

		}

	}



	if (forced_resume)

		pm_runtime_get_noresume(dev);

	pm_runtime_force_resume(dev);

	if (forced_resume)

		pm_runtime_put(dev);

	snd_power_change_state(card, SNDRV_CTL_POWER_D0);



	trace_azx_resume(chip);
@@ -1102,12 +1117,12 @@ static int azx_runtime_suspend(struct device *dev) 
	if (!azx_is_pm_ready(card))

		return 0;

	chip = card->private_data;

	if (!azx_has_pm_runtime(chip))

		return 0;



	/* enable controller wake up event */

	if (snd_power_get_state(card) == SNDRV_CTL_POWER_D0) {

		azx_writew(chip, WAKEEN, azx_readw(chip, WAKEEN) |

			   STATESTS_INT_MASK);

	}



	__azx_runtime_suspend(chip);

	trace_azx_runtime_suspend(chip);
@@ -1118,17 +1133,18 @@ static int azx_runtime_resume(struct device *dev) 
{

	struct snd_card *card = dev_get_drvdata(dev);

	struct azx *chip;

	bool from_rt = snd_power_get_state(card) == SNDRV_CTL_POWER_D0;



	if (!azx_is_pm_ready(card))

		return 0;

	chip = card->private_data;

	if (!azx_has_pm_runtime(chip))

		return 0;

	__azx_runtime_resume(chip, true);

	__azx_runtime_resume(chip, from_rt);



	/* disable controller Wake Up event*/

	if (from_rt) {

		azx_writew(chip, WAKEEN, azx_readw(chip, WAKEEN) &

			   ~STATESTS_INT_MASK);

	}



	trace_azx_runtime_resume(chip);

	return 0;

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