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>

2 files changed, 22 insertions, 30 deletions

diff --git a/sound/hda/hdac_component.c b/sound/hda/hdac_component.c
index 6e46a9c73aed..dd766414436b 100644
--- a/sound/hda/hdac_component.c
+++ b/sound/hda/hdac_component.c
@@ -54,38 +54,45 @@ EXPORT_SYMBOL_GPL(snd_hdac_set_codec_wakeup);
 /**
  * snd_hdac_display_power - Power up / down the power refcount
  * @bus: HDA core bus
+ * @idx: HDA codec address, pass HDA_CODEC_IDX_CONTROLLER for controller
  * @enable: power up or down
  *
- * This function is supposed to be used only by a HD-audio controller
- * driver that needs the interaction with graphics driver.
+ * This function is used by either HD-audio controller or codec driver that
+ * needs the interaction with graphics driver.
  *
- * This function manages a refcount and calls the get_power() and
+ * This function updates the power status, and calls the get_power() and
  * put_power() ops accordingly, toggling the codec wakeup, too.
  *
  * Returns zero for success or a negative error code.
  */
-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)
 {
 	struct drm_audio_component *acomp = bus->audio_component;
 
-	if (!acomp || !acomp->ops)
-		return -ENODEV;
-
 	dev_dbg(bus->dev, "display power %s\n",
 		enable ? "enable" : "disable");
+	if (enable)
+		set_bit(idx, &bus->display_power_status);
+	else
+		clear_bit(idx, &bus->display_power_status);
 
-	if (enable) {
-		if (!bus->drm_power_refcount++) {
+	if (!acomp || !acomp->ops)
+		return 0;
+
+	if (bus->display_power_status) {
+		if (!bus->display_power_active) {
 			if (acomp->ops->get_power)
 				acomp->ops->get_power(acomp->dev);
 			snd_hdac_set_codec_wakeup(bus, true);
 			snd_hdac_set_codec_wakeup(bus, false);
+			bus->display_power_active = true;
 		}
 	} else {
-		WARN_ON(!bus->drm_power_refcount);
-		if (!--bus->drm_power_refcount)
+		if (bus->display_power_active) {
 			if (acomp->ops->put_power)
 				acomp->ops->put_power(acomp->dev);
+			bus->display_power_active = false;
+		}
 	}
 
 	return 0;
@@ -321,10 +328,12 @@ int snd_hdac_acomp_exit(struct hdac_bus *bus)
 	if (!acomp)
 		return 0;
 
-	WARN_ON(bus->drm_power_refcount);
-	if (bus->drm_power_refcount > 0 && acomp->ops)
+	if (WARN_ON(bus->display_power_active) && acomp->ops)
 		acomp->ops->put_power(acomp->dev);
 
+	bus->display_power_active = false;
+	bus->display_power_status = 0;
+
 	component_master_del(dev, &hdac_component_master_ops);
 
 	bus->audio_component = NULL;
diff --git a/sound/hda/hdac_device.c b/sound/hda/hdac_device.c
index dbf02a3a8d2f..95b073ee4b32 100644
--- a/sound/hda/hdac_device.c
+++ b/sound/hda/hdac_device.c
@@ -622,23 +622,6 @@ int snd_hdac_power_down_pm(struct hdac_device *codec)
 EXPORT_SYMBOL_GPL(snd_hdac_power_down_pm);
 #endif
 
-/**
- * snd_hdac_link_power - Enable/disable the link power for a codec
- * @codec: the codec object
- * @bool: enable or disable the link power
- */
-int snd_hdac_link_power(struct hdac_device *codec, bool enable)
-{
-	if  (!codec->link_power_control)
-		return 0;
-
-	if  (codec->bus->ops->link_power)
-		return codec->bus->ops->link_power(codec->bus, enable);
-	else
-		return -EINVAL;
-}
-EXPORT_SYMBOL_GPL(snd_hdac_link_power);
-
 /* codec vendor labels */
 struct hda_vendor_id {
 	unsigned int id;