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: cec5b01f8f1c ("ASoC: max98357a: avoid speaker pop when playback startup")
Signed-off-by: Tzung-Bi Shih tzungbi@google.com --- Hi,
Not sure whether this fix is acceptable or not. Because in the document "timers-howto.txt", it states "In general, use of mdelay is discouraged and code should be refactored to allow for the use of msleep."
sound/soc/codecs/max98357a.c | 25 ++++--------------------- 1 file changed, 4 insertions(+), 21 deletions(-)
diff --git a/sound/soc/codecs/max98357a.c b/sound/soc/codecs/max98357a.c index 6f0e28f903bf..16313b973eaa 100644 --- a/sound/soc/codecs/max98357a.c +++ b/sound/soc/codecs/max98357a.c @@ -20,20 +20,10 @@ #include <sound/soc-dapm.h>
struct max98357a_priv { - struct delayed_work enable_sdmode_work; struct gpio_desc *sdmode; 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, 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_RESUME: case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: - queue_delayed_work(system_power_efficient_wq, - &max98357a->enable_sdmode_work, - msecs_to_jiffies(max98357a->sdmode_delay)); + mdelay(max98357a->sdmode_delay); + gpiod_set_value(max98357a->sdmode, 1); break; case SNDRV_PCM_TRIGGER_STOP: case SNDRV_PCM_TRIGGER_SUSPEND: case SNDRV_PCM_TRIGGER_PAUSE_PUSH: - cancel_delayed_work_sync(&max98357a->enable_sdmode_work); gpiod_set_value(max98357a->sdmode, 0); break; } @@ -112,30 +100,25 @@ static int max98357a_platform_probe(struct platform_device *pdev) int ret;
max98357a = devm_kzalloc(&pdev->dev, sizeof(*max98357a), GFP_KERNEL); - if (!max98357a) return -ENOMEM;
max98357a->sdmode = devm_gpiod_get_optional(&pdev->dev, "sdmode", GPIOD_OUT_LOW); - if (IS_ERR(max98357a->sdmode)) return PTR_ERR(max98357a->sdmode);
ret = device_property_read_u32(&pdev->dev, "sdmode-delay", &max98357a->sdmode_delay); - if (ret) { max98357a->sdmode_delay = 0; 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);
- INIT_DELAYED_WORK(&max98357a->enable_sdmode_work, - max98357a_enable_sdmode_work); - return devm_snd_soc_register_component(&pdev->dev, &max98357a_component_driver, &max98357a_dai_driver, 1);