[PATCH] ASoC: dapm: don't call pm_runtime_* on card device
runtime_usage of sound card has been observed to grow without bound. For example: $ cat /sys/devices/platform/sound/power/runtime_usage 46 $ sox -n -t s16 -r 48000 -c 2 - synth 1 sine 440 vol 0.1 | \ aplay -q -D hw:0,0 -f S16_LE -r 48000 -c 2 $ cat /sys/devices/platform/sound/power/runtime_usage 52
Commit 4e872a46823c ("ASoC: dapm: Don't force card bias level to be updated") stops to force update bias_level on card. If card doesn't provide set_bias_level callback, the snd_soc_dapm_set_bias_level() is equivalent to NOP for card device.
As a result, dapm_pre_sequence_async() doesn't change the bias_level of card device correctly. Thus, pm_runtime_get_sync() would be called in dapm_pre_sequence_async() without symmetric pm_runtime_put() in dapm_post_sequence_async().
Don't call pm_runtime_* on card device.
Signed-off-by: Tzung-Bi Shih tzungbi@google.com --- sound/soc/soc-dapm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
Hi, I'm not very sure if the patch makes sense.
I was considering: (1) update the bias_level of card device correctly (2) skip pm_runtime_* for card device
Per commit message on 4e872a46823c, I believe there is some context I'm not aware of it. Thus, the patch adopts (2).
diff --git a/sound/soc/soc-dapm.c b/sound/soc/soc-dapm.c index 5076299abf37..3273161e2787 100644 --- a/sound/soc/soc-dapm.c +++ b/sound/soc/soc-dapm.c @@ -1798,7 +1798,7 @@ static void dapm_pre_sequence_async(void *data, async_cookie_t cookie) /* If we're off and we're not supposed to go into STANDBY */ if (d->bias_level == SND_SOC_BIAS_OFF && d->target_bias_level != SND_SOC_BIAS_OFF) { - if (d->dev) + if (d->dev && cookie) pm_runtime_get_sync(d->dev);
ret = snd_soc_dapm_set_bias_level(d, SND_SOC_BIAS_STANDBY); @@ -1845,7 +1845,7 @@ static void dapm_post_sequence_async(void *data, async_cookie_t cookie) dev_err(d->dev, "ASoC: Failed to turn off bias: %d\n", ret);
- if (d->dev) + if (d->dev && cookie) pm_runtime_put(d->dev); }
On Fri, Jul 24, 2020 at 03:07:31PM +0800, Tzung-Bi Shih wrote:
Commit 4e872a46823c ("ASoC: dapm: Don't force card bias level to be updated") stops to force update bias_level on card. If card doesn't provide set_bias_level callback, the snd_soc_dapm_set_bias_level() is equivalent to NOP for card device.
As a result, dapm_pre_sequence_async() doesn't change the bias_level of card device correctly. Thus, pm_runtime_get_sync() would be called in dapm_pre_sequence_async() without symmetric pm_runtime_put() in dapm_post_sequence_async().
Don't call pm_runtime_* on card device.
Why is this a good fix, as opposed to only skipping the set_bias_level() bit?
On Fri, Jul 24, 2020 at 7:16 PM Mark Brown broonie@kernel.org wrote:
On Fri, Jul 24, 2020 at 03:07:31PM +0800, Tzung-Bi Shih wrote:
Commit 4e872a46823c ("ASoC: dapm: Don't force card bias level to be updated") stops to force update bias_level on card. If card doesn't provide set_bias_level callback, the snd_soc_dapm_set_bias_level() is equivalent to NOP for card device.
As a result, dapm_pre_sequence_async() doesn't change the bias_level of card device correctly. Thus, pm_runtime_get_sync() would be called in dapm_pre_sequence_async() without symmetric pm_runtime_put() in dapm_post_sequence_async().
Don't call pm_runtime_* on card device.
Why is this a good fix, as opposed to only skipping the set_bias_level() bit?
Did you mean: skip to call snd_soc_dapm_set_bias_level() in dapm_pre_sequence_async() and dapm_post_sequence_async()?
If so, skipping snd_soc_dapm_set_bias_level() won't fix the issue. The runtime_usage increases in pm_runtime_get() and decreases in pm_runtime_put().
Besides, snd_soc_dapm_set_bias_level() calls card->set_bias_level() and card->set_bias_level_post() if any. Skip to call snd_soc_dapm_set_bias_level() couldn't be a good idea. It may change some existing code behavior.
On Fri, Jul 24, 2020 at 08:26:13PM +0800, Tzung-Bi Shih wrote:
On Fri, Jul 24, 2020 at 7:16 PM Mark Brown broonie@kernel.org wrote:
Why is this a good fix, as opposed to only skipping the set_bias_level() bit?
Did you mean: skip to call snd_soc_dapm_set_bias_level() in dapm_pre_sequence_async() and dapm_post_sequence_async()?
No, I mean why not just add the missing puts which are currently being skipped due to being caught up with the bias level changes.
On Fri, Jul 24, 2020 at 9:02 PM Mark Brown broonie@kernel.org wrote:
On Fri, Jul 24, 2020 at 08:26:13PM +0800, Tzung-Bi Shih wrote:
On Fri, Jul 24, 2020 at 7:16 PM Mark Brown broonie@kernel.org wrote:
Why is this a good fix, as opposed to only skipping the set_bias_level() bit?
Did you mean: skip to call snd_soc_dapm_set_bias_level() in dapm_pre_sequence_async() and dapm_post_sequence_async()?
No, I mean why not just add the missing puts which are currently being skipped due to being caught up with the bias level changes.
The challenge I'm facing: (&card->dapm)->bias_level is always SND_SOC_BIAS_OFF. Commit 4e872a46823c stops to update it. It has nowhere to add the missing puts().
Ideally, if the bias_level goes away SND_SOC_BIAS_OFF in dapm_pre_sequence_async(), it calls pm_runtime_get(). If the bias_level goes into SND_SOC_BIAS_OFF in dapm_post_sequence_async(), it calls pm_runtime_put().
I tried to revert commit 4e872a46823c but it seems to screw the card state up.
Would you have any suggestions?
On Fri, Jul 24, 2020 at 10:41:41PM +0800, Tzung-Bi Shih wrote:
The challenge I'm facing: (&card->dapm)->bias_level is always SND_SOC_BIAS_OFF. Commit 4e872a46823c stops to update it. It has nowhere to add the missing puts().
Ideally, if the bias_level goes away SND_SOC_BIAS_OFF in dapm_pre_sequence_async(), it calls pm_runtime_get(). If the bias_level goes into SND_SOC_BIAS_OFF in dapm_post_sequence_async(), it calls pm_runtime_put().
Right, I see the problem now. This is probably fine.
On Fri, 24 Jul 2020 15:07:31 +0800, Tzung-Bi Shih wrote:
runtime_usage of sound card has been observed to grow without bound. For example: $ cat /sys/devices/platform/sound/power/runtime_usage 46 $ sox -n -t s16 -r 48000 -c 2 - synth 1 sine 440 vol 0.1 | \ aplay -q -D hw:0,0 -f S16_LE -r 48000 -c 2 $ cat /sys/devices/platform/sound/power/runtime_usage 52
[...]
Applied to
https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next
Thanks!
[1/1] ASoC: dapm: don't call pm_runtime_* on card device commit: 3aecfc72d7ad73330e7a6ebd0005738a8fd417ab
All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted.
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Thanks, Mark
participants (2)
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Mark Brown -
Tzung-Bi Shih