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[v2] ALSA: HDA: Early Forbid of runtime PM

Message ID 1598569536-9450-1-git-send-email-harshapriya.n@intel.com
State Accepted
Commit a0645daf16101bb9a6d87598c17e9a8b7bd60ea7
Headers show
Series [v2] ALSA: HDA: Early Forbid of runtime PM | expand

Commit Message

Harsha Priya Aug. 27, 2020, 11:05 p.m. UTC 
For certain codecs (like Realtek), pm_runtime_forbid() is invoked 
in the probe function after build_controls(). In a stress test, 
its observed occasionally that runtime PM calls are invoked 
before controls are built. This causes the codec to be
runtime suspended before probe completes. Because of this, not all
controls are enumerated correctly, and audio does not work until
system is rebooted.

This issue being common across all codecs, pm_runtime_forbid() is 
called when the codec object is created to fix this issue. 
A codec enables or disables runtime pm in its own probe function.

Multiple stress tests of 2000+ cycles has been done to test the fix.

Signed-off-by: Harsha Priya <harshapriya.n@intel.com>
Signed-off-by: Emmanuel Jillela <emmanuel.jillela@intel.com>
Reviewed-by: Kailang Yang <kailang@realtek.com>
---
 sound/pci/hda/hda_codec.c | 3 +++
 1 file changed, 3 insertions(+)

Comments

Takashi Iwai Aug. 31, 2020, 9:40 a.m. UTC | #1 
On Fri, 28 Aug 2020 19:06:51 +0200,
Jillela, Emmanuel wrote:
> 
> 
> > Subject: Re: [PATCH v2] ALSA: HDA: Early Forbid of runtime PM
> > 
> > Hey,
> > 
> > On Fri, 28 Aug 2020, Takashi Iwai wrote:
> > 
> > > On Fri, 28 Aug 2020 01:05:36 +0200, Harsha Priya wrote:
> > > > This issue being common across all codecs, pm_runtime_forbid() is
> > > > called when the codec object is created to fix this issue.
> > > > A codec enables or disables runtime pm in its own probe function.
> > >
> > > Thanks.  The only concern is about the influence on the relevant ASoC
> > > code, especially hdac_hda.c.
> > >
> > > Kai, could you check whether this still works?
> > 
> > I believe Harsha is testing mostly with ASoC, so hdac_hda.c should be covered.
> > 
> > I did queue a SOF CI job for this v2 patch and I'm seeing some failures in module
> > load/unload test that might be related and need checking before we merge:
> > 
> > https://sof-ci.01.org/linuxpr/PR2403/build4400/devicetest/
> > 
> > The actual runtime-PM tests in our test set pass, but module load/unload has failures >on
> > some platforms. I'll follow-up when I have a better understanding what goes wrong.
> > 
> > Br, Kai
> I am just trying to think ahead to get something that may work. We can add an if check around the pm_runtime_forbid like below
> If (!codec->auto_runtime_pm)
> 	Pm_runtime_forbid(&codec->core.dev)
> Do you think that will work??

snd_hda_codec_device_new() is called before setting the flag, so it's
no use for adding the conditional.


thanks,

Takashi
diff mbox series

Patch

diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index e96a87f1b611..a356c21edb90 100644
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -1000,6 +1000,9 @@  int snd_hda_codec_device_new(struct hda_bus *bus, struct snd_card *card,
 	if (err < 0)
 		goto error;
 
+	/* PM runtime needs to be enabled later after binding codec */
+	pm_runtime_forbid(&codec->core.dev);
+
 	return 0;
 
  error: