ALSA: hda: Refactor display power management

The current HD-audio code manages the DRM audio power via too complex
redirections, and this seems even still unbalanced in a corner case as
Intel DRM CI has been intermittently reporting.  This patch is a big
surgery for addressing the complexity and the possible unbalance.

Basically the patch changes the display PM in the following ways:

- Both HD-audio controller and codec drivers call a single helper,
  snd_hdac_display_power().  (Formerly, the display power control from
  a codec was done indirectly via link_power bus ops.)

- snd_hdac_display_power() receives the codec address index.  For
  turning on/off from the controller, pass HDA_CODEC_IDX_CONTROLLER.

- snd_hdac_display_power() doesn't manage refcounts any longer, but
  keeps the power status in bitmap.  If any of controller or codecs is
  turned on, the function updates the DRM power state via get_power()
  or put_power().

Also this refactor allows us more cleanup:

- The link_power bus ops is dropped, so there is no longer indirect
  management, as mentioned in the above.

- hdac_device link_power_control flag is moved to hda_codec
  display_power_control flag, as it's only for HDA legacy.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=106525
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 8 insertions, 2 deletions

diff --git a/include/sound/hda_component.h b/include/sound/hda_component.h
index 78626cde7081..767c8d8a0230 100644
--- a/include/sound/hda_component.h
+++ b/include/sound/hda_component.h
@@ -5,10 +5,15 @@
 #define __SOUND_HDA_COMPONENT_H
 
 #include <drm/drm_audio_component.h>
+#include <sound/hdaudio.h>
+
+/* virtual idx for controller */
+#define HDA_CODEC_IDX_CONTROLLER	HDA_MAX_CODECS
 
 #ifdef CONFIG_SND_HDA_COMPONENT
 int snd_hdac_set_codec_wakeup(struct hdac_bus *bus, bool enable);
-int snd_hdac_display_power(struct hdac_bus *bus, bool enable);
+int snd_hdac_display_power(struct hdac_bus *bus, unsigned int idx,
+			   bool enable);
 int snd_hdac_sync_audio_rate(struct hdac_device *codec, hda_nid_t nid,
 			     int dev_id, int rate);
 int snd_hdac_acomp_get_eld(struct hdac_device *codec, hda_nid_t nid, int dev_id,
@@ -25,7 +30,8 @@ static inline int snd_hdac_set_codec_wakeup(struct hdac_bus *bus, bool enable)
 {
 	return 0;
 }
-static inline int snd_hdac_display_power(struct hdac_bus *bus, bool enable)
+static inline int snd_hdac_display_power(struct hdac_bus *bus,
+					 unsigned int idx, bool enable)
 {
 	return 0;
 }