Messages in this thread | | | Date | Mon, 18 Jan 2021 14:21:36 +0100 | From | Takashi Iwai <> | Subject | Re: [PATCH] ALSA: hda: Balance runtime/system PM if direct-complete is disabled |
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On Mon, 18 Jan 2021 14:09:36 +0100, Kai-Heng Feng wrote: > > HDA controller can't be runtime-suspended after commit 215a22ed31a1 > ("ALSA: hda: Refactor codjc PM to use direct-complete optimization"), > which enables direct-complete for HDA codec. > > The HDA codec driver didn't expect direct-complete will be disabled > after it returns a positive value from prepare() callback. However, > there are some places that PM core can disable direct-complete. For > instance, system hibernation or when codec has subordinates like LEDs.
Hmm. This sounds rather like the approach using the direct-complete isn't well suited for the purpose? The increasing number of regression reports worries me.
> So if a device is prepared for direct-complete but PM core still calls > codec's suspend or freeze callback, resume the device to keep PM > operations balanced.
I find the ping-pong of the resume/suspend there a bit odd. It's no refcount management but it invokes the real resume there, which is involved with lots of operations.
Can we rather skip the hda_codec_suspend() call instead (while changing dev->power.power_state)?
thanks,
Takashi
> Reported-by: Kenneth R. Crudup <kenny@panix.com> > Fixes: 215a22ed31a1 ("ALSA: hda: Refactor codec PM to use direct-complete optimization") > Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com> > --- > sound/pci/hda/hda_codec.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c > index 687216e74526..0afbced979df 100644 > --- a/sound/pci/hda/hda_codec.c > +++ b/sound/pci/hda/hda_codec.c > @@ -2997,6 +2997,9 @@ static void hda_codec_pm_complete(struct device *dev) > > static int hda_codec_pm_suspend(struct device *dev) > { > + if (pm_runtime_status_suspended(dev)) > + pm_runtime_resume(dev); > + > dev->power.power_state = PMSG_SUSPEND; > return hda_codec_suspend(dev); > } > @@ -3009,6 +3012,9 @@ static int hda_codec_pm_resume(struct device *dev) > > static int hda_codec_pm_freeze(struct device *dev) > { > + if (pm_runtime_status_suspended(dev)) > + pm_runtime_resume(dev); > + > dev->power.power_state = PMSG_FREEZE; > return hda_codec_suspend(dev); > } > -- > 2.29.2 >
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