On Fri, 11 Jan 2019 15:24:30 +0100,
Takashi Iwai wrote:
>
> On Fri, 11 Jan 2019 14:34:34 +0100,
> Takashi Iwai wrote:
> >
> > On Fri, 11 Jan 2019 06:20:23 +0100,
> > Yang, Libin wrote:
> > >
> > > The below patch may have a small confliction that the trigger will be
> > > called twice as our SOF has already call snd_pcm_suspend() in card
> > > suspend.
> >
> > It should be no problem, snd_pcm_suspend() can be called multiple
> > times. If it's already suspended, just nothing happens.
>
> Thinking of this problem again, does a patch like below work instead?
> This looks like a better and more generic solution.
>
> What I'm not quite sure is whether the device suspend order between
> PCM device and HD-audio codec device is guaranteed. I guess yes,
> because the PCM device is registered always after the codec. But ASoC
> might have another weirdness :)
... and further reading revealed that my afraid is right -- ASoC is
another beast. Basically PM in ASoC requires *not* to be done by the
usual device PM callbacks. snd_soc_suspend() does the whole suspend
jobs sequentially. So, what you need for Intel ASoC driver is to do
suspend/resume with the component callbacks instead of device PM ops.
Currently the plumbing of hdac-hdmi driver is in a half-baked state.
> If this patch works, basically we can get rid of all external callers
> of snd_pcm_suspend() & co. That'll be a nice cleanup.
OTOH, the statement above is still true for non-ASoC drivers. So we'd
end up needing an extra flag or such to prevent the PCM device PM ops
for ASoC, while using this for the rest.
thanks,
Takashi
>
>
> thanks,
>
> Takashi
>
> ---
> diff --git a/sound/core/pcm.c b/sound/core/pcm.c
> index 01b9d62eef14..d8d57336b8b8 100644
> --- a/sound/core/pcm.c
> +++ b/sound/core/pcm.c
> @@ -683,6 +683,25 @@ static inline int snd_pcm_substream_proc_done(struct snd_pcm_substream *substrea
>
> static const struct attribute_group *pcm_dev_attr_groups[];
>
> +#ifdef CONFIG_PM_SLEEP
> +static int do_pcm_suspend(struct device *dev)
> +{
> + struct snd_pcm_str *pstr = container_of(dev, struct snd_pcm_str, dev);
> +
> + snd_pcm_suspend_all(pstr->pcm);
> + return 0;
> +}
> +#endif
> +
> +static const struct dev_pm_ops pcm_dev_pm_ops = {
> + SET_SYSTEM_SLEEP_PM_OPS(do_pcm_suspend, NULL)
> +};
> +
> +static const struct device_type pcm_dev_type = {
> + .name = "pcm",
> + .pm = &pcm_dev_pm_ops,
> +};
> +
> /**
> * snd_pcm_new_stream - create a new PCM stream
> * @pcm: the pcm instance
> @@ -713,6 +732,7 @@ int snd_pcm_new_stream(struct snd_pcm *pcm, int stream, int substream_count)
>
> snd_device_initialize(&pstr->dev, pcm->card);
> pstr->dev.groups = pcm_dev_attr_groups;
> + pstr->dev.type = &pcm_dev_type;
> dev_set_name(&pstr->dev, "pcmC%iD%i%c", pcm->card->number, pcm->device,
> stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
>
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