• Takashi Iwai's avatar
    ALSA: hda - Use standard runtime PM for codec power-save control · cc72da7d
    Takashi Iwai authored
    Like the previous transition of suspend/resume, now move the
    power-save code to the standard runtime PM.  As usual for runtime PM,
    it's a bit tricky, but this simplified codes a lot in the end.
    For keeping the usage compatibility, power_save module option still
    controls the whole power-saving behavior on all codecs.  The value is
    translated to pm_runtime_*_autosuspend() and pm_runtime_allow() /
    pm_runtime_forbid() calls.
    snd_hda_power_up() and snd_hda_power_down() are translated to
    pm_runtime_get_sync() and pm_runtime_put_autosuspend(), respectively.
    Since we can do call pm_runtime_get_sync() more reliably, the sync
    version is used always and snd_hda_power_up_d3wait() is dropped.
    Another slight difference is that snd_hda_power_up()/down() don't call
    runtime_pm code during the suspend/resume transition phase.  Calling
    them there isn't safe unlike our own code, resulted in unexpected
    behavior (endless wakeups).
    The hda_power_count tracepoint was removed, as it doesn't match well
    with the new code.
    Last but not least, we need to set ignore_children flag in the parent
    dev.power field so that the runtime PM of the controller chip won't
    get confused.  The notification is still done in the bus pm_notify
    callback.  We'll get rid of this hack in the later patch.
    Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
hda_codec.c 148 KB