[alsa-devel] [PATCH v2] ASoC: Intel: Reset hw_ptr on resume trigger

[Cheng-yi Chiang]

+Jarkko Nikula

Hi Keyon,
  Sorry for the late reply. I spent some time trying to figure out
previous suspend resume patch in BYT.

  From the patch for restore_stream flag:
https://patchwork.kernel.org/patch/4706611/,  the restore_stream flag
means that ADSP was in power off state during system suspend/resume
cycle. You are right that the resuming won't play from the pausing
point of the last suspending. I am not sure whether it is intended in
ADSP coming back from power off case. Jarkko and Ullysses might have
better idea on this.

In my testing I have found that this patch sometimes causes playback
failure upon resume. I have put the logs in
https://bugs.chromium.org/p/chromium/issues/detail?id=752107. I think
we should not merge this until it is resolved. I have cc'ed Intel
folks on the issue.

Thanks!

On Tue, Aug 1, 2017 at 1:04 PM, Keyon Jie <yang.jie at linux.intel.com> wrote:
>
> On 2017年08月01日 11:30, Vinod Koul wrote:
>>
>> On Mon, Jul 31, 2017 at 06:47:34PM +0800, Cheng-Yi Chiang wrote:
>>>
>>> From: "U. Artie Eoff" <ullysses.a.eoff at intel.com>
>>>
>>> Reset the hw_ptr before queuing the restore_stream_context
>>> work to eradicate a nasty white audio noise on resume.
>>
>>
>> Liam, Jie? This on legacy BYT driver..
>>
>>>
>>> Tested-by: Cheng-Yi Chiang <cychiang at chromium.org>
>>> Signed-off-by: U. Artie Eoff <ullysses.a.eoff at intel.com>
>>> Signed-off-by: Cheng-Yi Chiang <cychiang at chromium.org>
>>> ---
>>>   sound/soc/intel/baytrail/sst-baytrail-pcm.c | 4 +++-
>>>   1 file changed, 3 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/sound/soc/intel/baytrail/sst-baytrail-pcm.c
>>> b/sound/soc/intel/baytrail/sst-baytrail-pcm.c
>>> index 4765ad474544..e0db7070cd42 100644
>>> --- a/sound/soc/intel/baytrail/sst-baytrail-pcm.c
>>> +++ b/sound/soc/intel/baytrail/sst-baytrail-pcm.c
>>> @@ -187,8 +187,10 @@ static int sst_byt_pcm_trigger(struct
>>> snd_pcm_substream *substream, int cmd)
>>>                 sst_byt_stream_start(byt, pcm_data->stream, 0);
>>>                 break;
>>>         case SNDRV_PCM_TRIGGER_RESUME:
>>> -               if (pdata->restore_stream == true)
>>> +               if (pdata->restore_stream == true) {
>>> +                       pcm_data->hw_ptr = 0;
>
>
> Won't this break the hw_ptr and make the resuming won't play from the
> pausing point of the last suspending?
>
> Thanks,
> ~Keyon
>
>
>>>                         schedule_work(&pcm_data->work);
>>> +               }
>>>                 else
>>>                         sst_byt_stream_resume(byt, pcm_data->stream);
>>>                 break;
>>> --
>>> 2.12.2
>>>
>>
>