[alsa-devel] ASoC CODEC power management on reboot
I've run into a problem where when the system reboots the audio starts playing random data. I suspect that this is due to the CODEC being left powered and when the during/after the reset process the GPIO lines which form the I2S bus are left floating.
Should the ASoC (possibly DAPM) layer sort out powering down the CODEC before reboot, or should it be down to the codec or the mapping driver to do this?
On Mon, Jun 22, 2009 at 12:32:50PM +0100, Mark Brown wrote:
On Mon, Jun 22, 2009 at 12:13:23PM +0100, Ben Dooks wrote:
Should the ASoC (possibly DAPM) layer sort out powering down the CODEC before reboot, or should it be down to the codec or the mapping driver to do this?
Core.
Please try this (completely untested) patch:
On Mon, Jun 22, 2009 at 01:18:26PM +0100, Mark Brown wrote:
On Mon, Jun 22, 2009 at 12:32:50PM +0100, Mark Brown wrote:
On Mon, Jun 22, 2009 at 12:13:23PM +0100, Ben Dooks wrote:
Should the ASoC (possibly DAPM) layer sort out powering down the CODEC before reboot, or should it be down to the codec or the mapping driver to do this?
Core.
Please try this (completely untested) patch:
From 506921be0ce5b96c3761c771a9356f2c53bd6628 Mon Sep 17 00:00:00 2001
From: Mark Brown broonie@opensource.wolfsonmicro.com Date: Mon, 22 Jun 2009 13:16:51 +0100 Subject: [PATCH] ASoC: Add a shutdown callback
Ensure that the audio subsystem is powered down cleanly when the system shuts down by providing a shutdown operation. This ensures that all the components have been returned to an off state cleanly which should avoid audio issues from partially charged capacitors or noise on digital inputs if the system is restarted quickly.
Right, so far this seems to have worked.
Signed-off-by: Mark Brown broonie@opensource.wolfsonmicro.com
Tested-by: Ben Dooks ben-linux@fluff.org
include/sound/soc-dapm.h | 1 + sound/soc/soc-core.c | 16 ++++++++++++++++ sound/soc/soc-dapm.c | 29 +++++++++++++++++++++++++++++ 3 files changed, 46 insertions(+), 0 deletions(-)
diff --git a/include/sound/soc-dapm.h b/include/sound/soc-dapm.h index ec8a45f..35814ce 100644 --- a/include/sound/soc-dapm.h +++ b/include/sound/soc-dapm.h @@ -279,6 +279,7 @@ int snd_soc_dapm_add_routes(struct snd_soc_codec *codec, /* dapm events */ int snd_soc_dapm_stream_event(struct snd_soc_codec *codec, char *stream, int event); +void snd_soc_dapm_shutdown(struct snd_soc_device *socdev);
/* dapm sys fs - used by the core */ int snd_soc_dapm_sys_add(struct device *dev); diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c index 4414117..55d45c4 100644 --- a/sound/soc/soc-core.c +++ b/sound/soc/soc-core.c @@ -1020,6 +1020,21 @@ static int soc_remove(struct platform_device *pdev) return 0; }
+static void soc_shutdown(struct platform_device *pdev) +{
- struct snd_soc_device *socdev = platform_get_drvdata(pdev);
- struct snd_soc_card *card = socdev->card;
- if (!card->instantiated)
return;- /* Flush out pmdown_time work - we actually do want to run it
* now, we're shutting down so no imminent restart. */- run_delayed_work(&card->delayed_work);
- snd_soc_dapm_shutdown(socdev);
+}
/* ASoC platform driver */ static struct platform_driver soc_driver = { .driver = { @@ -1030,6 +1045,7 @@ static struct platform_driver soc_driver = { .remove = soc_remove, .suspend = soc_suspend, .resume = soc_resume,
- .shutdown = soc_shutdown,
};
/* create a new pcm */ diff --git a/sound/soc/soc-dapm.c b/sound/soc/soc-dapm.c index 6534359..b9129ef 100644 --- a/sound/soc/soc-dapm.c +++ b/sound/soc/soc-dapm.c @@ -2032,6 +2032,35 @@ void snd_soc_dapm_free(struct snd_soc_device *socdev) } EXPORT_SYMBOL_GPL(snd_soc_dapm_free);
+/*
- snd_soc_dapm_shutdown - callback for system shutdown
- */
+void snd_soc_dapm_shutdown(struct snd_soc_device *socdev) +{
- struct snd_soc_codec *codec = socdev->card->codec;
- struct snd_soc_dapm_widget *w;
- LIST_HEAD(down_list);
- int powerdown = 0;
- list_for_each_entry(w, &codec->dapm_widgets, list) {
if (w->power) {dapm_seq_insert(w, &down_list, dapm_down_seq);powerdown = 1;}- }
- /* If there were no widgets to power down we're already in
* standby.*/- if (powerdown) {
snd_soc_dapm_set_bias_level(socdev, SND_SOC_BIAS_PREPARE);dapm_seq_run(codec, &down_list, 0, dapm_down_seq);snd_soc_dapm_set_bias_level(socdev, SND_SOC_BIAS_STANDBY);- }
- snd_soc_dapm_set_bias_level(socdev, SND_SOC_BIAS_OFF);
+}
/* Module information */ MODULE_AUTHOR("Liam Girdwood, lrg@slimlogic.co.uk"); MODULE_DESCRIPTION("Dynamic Audio Power Management core for ALSA SoC"); -- 1.6.3.1
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participants (2)
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Ben Dooks -
Mark Brown