ALSA: hda: Skip controller resume if not needed

The HD-audio controller does system-suspend and resume operations by
directly calling its helpers __azx_runtime_suspend() and
__azx_runtime_resume().  However, in general, we don't have to resume
always the device fully at the system resume; typically, if a device
has been runtime-suspended, we can leave it to runtime resume.

Usually for achieving this, the driver would call
pm_runtime_force_suspend() and pm_runtime_force_resume() pairs in the
system suspend and resume ops.  Unfortunately, this doesn't work for
the resume path in our case.  For handling the jack detection at the
system resume, a child codec device may need the (literally) forcibly
resume even if it's been runtime-suspended, and for that, the
controller device must be also resumed even if it's been suspended.

This patch is an attempt to improve the situation.  It replaces the
direct __azx_runtime_suspend()/_resume() calls with with
pm_runtime_force_suspend() and pm_runtime_force_resume() with a slight
trick as we've done for the codec side.  More exactly:

- azx_has_pm_runtime() check is dropped from azx_runtime_suspend() and
  azx_runtime_resume(), so that it can be properly executed from the
  system-suspend/resume path

- The WAKEEN handling depends on the card's power state now; it's set
  and cleared only for the runtime-suspend

- azx_resume() checks whether any codec may need the forcible resume
  beforehand.  If the forcible resume is required, it does temporary
  PM refcount up/down for actually triggering the runtime resume.

- A new helper function, hda_codec_need_resume(), is introduced for
  checking whether the codec needs a forcible runtime-resume, and the
  existing code is rewritten with that.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=207043
Link: https://lore.kernel.org/r/20200413082034.25166-6-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 5 insertions, 0 deletions

diff --git a/include/sound/hda_codec.h b/include/sound/hda_codec.h
index 3ee8036f5436..225154a4f2ed 100644
--- a/include/sound/hda_codec.h
+++ b/include/sound/hda_codec.h
@@ -494,6 +494,11 @@ void snd_hda_update_power_acct(struct hda_codec *codec);
 static inline void snd_hda_set_power_save(struct hda_bus *bus, int delay) {}
 #endif
 
+static inline bool hda_codec_need_resume(struct hda_codec *codec)
+{
+	return !codec->relaxed_resume && codec->jacktbl.used;
+}
+
 #ifdef CONFIG_SND_HDA_PATCH_LOADER
 /*
  * patch firmware