Commit 6ed25978 authored by Andy Green's avatar Andy Green Committed by Jaroslav Kysela
Browse files

ALSA: ASoC: Don't block system resume 



On OpenMoko soc-audio resume is taking 700ms of the whole resume time of
1.3s, dominated by writes to the codec over I2C.  This patch shunts the
resume guts into a workqueue which then is done asynchronously.

The "card" is locked using the ALSA power state APIs as suggested by
Mark Brown.

[Added fix for race with resume to suspend and fixed a couple of nits
from checkpatch -- broonie.]

Signed-off-by: default avatarAndy Green <andy@openmoko.com>
Signed-off-by: default avatarMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
Signed-off-by: default avatarJaroslav Kysela <perex@perex.cz>
parent abb68c26

include/sound/soc.h

+1 −0
Original line number Diff line number Diff line
@@ -510,6 +510,7 @@ struct snd_soc_device { 
	struct snd_soc_codec *codec;

	struct snd_soc_codec_device *codec_dev;

	struct delayed_work delayed_work;

	struct work_struct deferred_resume_work;

	void *codec_data;

};

sound/soc/soc-core.c

+43 −3
Original line number Diff line number Diff line
@@ -639,6 +639,16 @@ static int soc_suspend(struct platform_device *pdev, pm_message_t state) 
	struct snd_soc_codec *codec = socdev->codec;

	int i;



	/* Due to the resume being scheduled into a workqueue we could

	* suspend before that's finished - wait for it to complete.

	 */

	snd_power_lock(codec->card);

	snd_power_wait(codec->card, SNDRV_CTL_POWER_D0);

	snd_power_unlock(codec->card);



	/* we're going to block userspace touching us until resume completes */

	snd_power_change_state(codec->card, SNDRV_CTL_POWER_D3hot);



	/* mute any active DAC's */

	for (i = 0; i < machine->num_links; i++) {

		struct snd_soc_codec_dai *dai = machine->dai_link[i].codec_dai;
@@ -691,16 +701,27 @@ static int soc_suspend(struct platform_device *pdev, pm_message_t state) 
	return 0;

}



/* powers up audio subsystem after a suspend */

static int soc_resume(struct platform_device *pdev)

/* deferred resume work, so resume can complete before we finished

 * setting our codec back up, which can be very slow on I2C

 */

static void soc_resume_deferred(struct work_struct *work)

{

	struct snd_soc_device *socdev = platform_get_drvdata(pdev);

	struct snd_soc_device *socdev = container_of(work,

						     struct snd_soc_device,

						     deferred_resume_work);

	struct snd_soc_machine *machine = socdev->machine;

	struct snd_soc_platform *platform = socdev->platform;

	struct snd_soc_codec_device *codec_dev = socdev->codec_dev;

	struct snd_soc_codec *codec = socdev->codec;

	struct platform_device *pdev = to_platform_device(socdev->dev);

	int i;



	/* our power state is still SNDRV_CTL_POWER_D3hot from suspend time,

	 * so userspace apps are blocked from touching us

	 */



	dev_info(socdev->dev, "starting resume work\n");



	if (machine->resume_pre)

		machine->resume_pre(pdev);
@@ -742,6 +763,22 @@ static int soc_resume(struct platform_device *pdev) 
	if (machine->resume_post)

		machine->resume_post(pdev);



	dev_info(socdev->dev, "resume work completed\n");



	/* userspace can access us now we are back as we were before */

	snd_power_change_state(codec->card, SNDRV_CTL_POWER_D0);

}



/* powers up audio subsystem after a suspend */

static int soc_resume(struct platform_device *pdev)

{

	struct snd_soc_device *socdev = platform_get_drvdata(pdev);



	dev_info(socdev->dev, "scheduling resume work\n");



	if (!schedule_work(&socdev->deferred_resume_work))

		dev_err(socdev->dev, "work item may be lost\n");



	return 0;

}
@@ -788,6 +825,9 @@ static int soc_probe(struct platform_device *pdev) 


	/* DAPM stream work */

	INIT_DELAYED_WORK(&socdev->delayed_work, close_delayed_work);

	/* deferred resume work */

	INIT_WORK(&socdev->deferred_resume_work, soc_resume_deferred);



	return 0;



platform_err:

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