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

[David Henningsson]

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.

Could it be that the card gives wrong info if unsol is not enabled, or 
perhaps needs SET_PIN_SENSE in that case? I don't know.

But yeah, I'll have to wait with this patch then until I've verified 
more things.

Thanks.


-- 
David Henningsson, Canonical Ltd.
https://launchpad.net/~diwic