[alsa-devel] [PATCH] ALSA: hda - fix broken HDMI jack detection after S3

[Takashi Iwai]

At Wed, 22 Aug 2012 14:39:17 +0200,
David Henningsson wrote:
> 
> On 08/22/2012 02:22 PM, Takashi Iwai wrote:
> > At Wed, 22 Aug 2012 14:01:41 +0200,
> > David Henningsson wrote:
> >>
> >> The HDMI codec (an NVIDIA one in this case) forgot that its pins
> >> were unsol enabled, while it was suspended. Therefore jack detection
> >> was broken after S3.
> >> With this patch, we reenable the unsol events on resume,
> >> and also do an extra check afterwards, to see if the HDMI monitor was
> >> plugged/unplugged while in S3.
> >>
> >> Cc: stable at kernel.org (3.3+)
> >> BugLink: https://bugs.launchpad.net/bugs/1040030
> >> Signed-off-by: David Henningsson <david.henningsson at canonical.com>
> >> ---
> >>   sound/pci/hda/patch_hdmi.c |   13 +++++++++++++
> >>   1 file changed, 13 insertions(+)
> >>
> >> diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
> >> index 8f23374..6a3ac05 100644
> >> --- a/sound/pci/hda/patch_hdmi.c
> >> +++ b/sound/pci/hda/patch_hdmi.c
> >> @@ -1315,6 +1315,16 @@ static int generic_hdmi_init(struct hda_codec *codec)
> >>   	return 0;
> >>   }
> >>
> >> +#ifdef CONFIG_PM
> >> +static int generic_hdmi_resume(struct hda_codec *codec)
> >> +{
> >> +	snd_hda_codec_resume_cache(codec);
> >> +	snd_hda_jack_set_dirty_all(codec);
> >> +	snd_hda_jack_report_sync(codec);
> >> +	return 0;
> >
> > Hm, is this really needed?
> >
> > snd_hda_jack_set_dirty_all() is already called in
> > hda_call_codec_resume(), and snd_hda_jack_report_sync() is called in
> > the init callback.
> 
> The tester (who has the hardware) has gone for the day, so I can't 
> really verify different scenarios right now, but after having looked at 
> hda_call_codec_resume I see what you mean...
> 
> I do notice one difference though - the order. 
> snd_hda_codec_resume_cache, which is what writes the unsol_enable verbs, 
> should probably be before the set_dirty_all / report_sync. If not for 
> anything else, so for the race condition of somebody plugging/unplugging 
> the monitor after checking the jack but before the unsol is enabled.

Calling snd_hda_jack_report_sync() in init means that all jacks are
checked at first, then the caches are resumed.  So this won't change
ENABLE_UNSOL verb setups.

The bug report doesn't give any details, so it's hard to guess what
actually doesn't work.  alsa-info.sh output before and after suspend
would be helpful to understand.


Takashi