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ASoC: max98357a: use mdelay for sdmode-delay

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max98357a_daiops_trigger() is possible to be called in atomic context if
the .nonatomic flag is equal to 0 in the DAI links.

When cancel_delayed_work_sync() in max98357a_daiops_trigger() is called
in atomic context, kernel emits the following message: "BUG: sleeping
function called from invalid context".

According to the DT binding document, value less than or equal to 5ms of
sdmod-delay should be sufficient to avoid the pop noise.  Use mdelay
(i.e. busy loop) for such low delay should be acceptable.

Fixes: cec5b01f8f ("ASoC: max98357a: avoid speaker pop when playback
startup")

Signed-off-by: Tzung-Bi Shih <tzungbi@google.com>
Link: https://lore.kernel.org/r/20190708141901.68797-1-tzungbi@google.com
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Tzung-Bi Shih 2019-07-08 22:19:01 +08:00 committed by Mark Brown
parent 87a6fe80d5
commit 6cd249cfad
No known key found for this signature in database
GPG Key ID: 24D68B725D5487D0
1 changed files with 4 additions and 21 deletions
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25
sound/soc/codecs/max98357a.c
View File

@ -20,20 +20,10 @@
#include <sound/soc-dapm.h> #include <sound/soc-dapm.h>
struct max98357a_priv { struct max98357a_priv {
struct delayed_work enable_sdmode_work;
struct gpio_desc *sdmode; struct gpio_desc *sdmode;
unsigned int sdmode_delay; unsigned int sdmode_delay;
}; };
static void max98357a_enable_sdmode_work(struct work_struct *work)
{
struct max98357a_priv *max98357a =
container_of(work, struct max98357a_priv,
enable_sdmode_work.work);
gpiod_set_value(max98357a->sdmode, 1);
}
static int max98357a_daiops_trigger(struct snd_pcm_substream *substream, static int max98357a_daiops_trigger(struct snd_pcm_substream *substream,
int cmd, struct snd_soc_dai *dai) int cmd, struct snd_soc_dai *dai)
{ {
@ -46,14 +36,12 @@ static int max98357a_daiops_trigger(struct snd_pcm_substream *substream,
case SNDRV_PCM_TRIGGER_START: case SNDRV_PCM_TRIGGER_START:
case SNDRV_PCM_TRIGGER_RESUME: case SNDRV_PCM_TRIGGER_RESUME:
case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
queue_delayed_work(system_power_efficient_wq, mdelay(max98357a->sdmode_delay);
&max98357a->enable_sdmode_work, gpiod_set_value(max98357a->sdmode, 1);
msecs_to_jiffies(max98357a->sdmode_delay));
break; break;
case SNDRV_PCM_TRIGGER_STOP: case SNDRV_PCM_TRIGGER_STOP:
case SNDRV_PCM_TRIGGER_SUSPEND: case SNDRV_PCM_TRIGGER_SUSPEND:
case SNDRV_PCM_TRIGGER_PAUSE_PUSH: case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
cancel_delayed_work_sync(&max98357a->enable_sdmode_work);
gpiod_set_value(max98357a->sdmode, 0); gpiod_set_value(max98357a->sdmode, 0);
break; break;
} }
@ -112,30 +100,25 @@ static int max98357a_platform_probe(struct platform_device *pdev)
int ret; int ret;
max98357a = devm_kzalloc(&pdev->dev, sizeof(*max98357a), GFP_KERNEL); max98357a = devm_kzalloc(&pdev->dev, sizeof(*max98357a), GFP_KERNEL);
if (!max98357a) if (!max98357a)
return -ENOMEM; return -ENOMEM;
max98357a->sdmode = devm_gpiod_get_optional(&pdev->dev, max98357a->sdmode = devm_gpiod_get_optional(&pdev->dev,
"sdmode", GPIOD_OUT_LOW); "sdmode", GPIOD_OUT_LOW);
if (IS_ERR(max98357a->sdmode)) if (IS_ERR(max98357a->sdmode))
return PTR_ERR(max98357a->sdmode); return PTR_ERR(max98357a->sdmode);
ret = device_property_read_u32(&pdev->dev, "sdmode-delay", ret = device_property_read_u32(&pdev->dev, "sdmode-delay",
&max98357a->sdmode_delay); &max98357a->sdmode_delay);
if (ret) { if (ret) {
max98357a->sdmode_delay = 0; max98357a->sdmode_delay = 0;
dev_dbg(&pdev->dev, dev_dbg(&pdev->dev,
"no optional property 'sdmode-delay' found, default: no delay\n"); "no optional property 'sdmode-delay' found, "
"default: no delay\n");
} }
dev_set_drvdata(&pdev->dev, max98357a); dev_set_drvdata(&pdev->dev, max98357a);
INIT_DELAYED_WORK(&max98357a->enable_sdmode_work,
max98357a_enable_sdmode_work);
return devm_snd_soc_register_component(&pdev->dev, return devm_snd_soc_register_component(&pdev->dev,
&max98357a_component_driver, &max98357a_component_driver,
&max98357a_dai_driver, 1); &max98357a_dai_driver, 1);