ALSA: hda - Allow runtime PM for controller if component notifier is used

Currently we disallow the runtime PM of the HD-audio controller if
it's bound with HDMI/DP on Nvidia / AMD unless it's for dGPU.  This is
for keeping the link up to get the proper notification for ELD
hotplug.

As explained in the commit 37a3a98e ("ALSA: hda - Enable runtime
PM only for discrete GPU"), this keep-power-up behavior is rather a
stop-gap solution until the ELD notification via audio component.
And now we finally got the audio component for these graphics drivers
via commit ade49db3 ("ALSA: hda/hdmi - Allow audio component for
AMD/ATI and Nvidia HDMI"), so it's time to change.

This patch makes HD-audio controller again runtime-suspendable when
the device gets bound with audio component in HDMI codec driver.  For
making it easier to access from the codec driver, move the flag into
the common hda_bus object instead of hda_intel flag.  Also rename it
to keep_power, to indicate the actual meaning.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

include/sound/hda_codec.h

@@ -59,6 +59,7 @@ struct hda_bus {
 	unsigned int in_reset:1;	/* during reset operation */
 	unsigned int no_response_fallback:1; /* don't fallback at RIRB error */
 	unsigned int bus_probing :1;	/* during probing process */
+	unsigned int keep_power:1;	/* keep power up for notification */
 
 	int primary_dig_out_type;	/* primary digital out PCM type */
 	unsigned int mixer_assigned;	/* codec addr for mixer name */

sound/pci/hda/hda_intel.c

@@ -356,7 +356,7 @@ enum {
  */
 #ifdef SUPPORT_VGA_SWITCHEROO
 #define use_vga_switcheroo(chip)	((chip)->use_vga_switcheroo)
-#define needs_eld_notify_link(chip)	((chip)->need_eld_notify_link)
+#define needs_eld_notify_link(chip)	((chip)->bus.keep_power)
 #else
 #define use_vga_switcheroo(chip)	0
 #define needs_eld_notify_link(chip)	false
@@ -1145,7 +1145,7 @@ static int azx_runtime_idle(struct device *dev)
 		return -EBUSY;
 
 	/* ELD notification gets broken when HD-audio bus is off */
-	if (needs_eld_notify_link(hda))
+	if (needs_eld_notify_link(chip))
 		return -EBUSY;
 
 	return 0;
@@ -1256,7 +1256,7 @@ static void setup_vga_switcheroo_runtime_pm(struct azx *chip)
 	struct hda_intel *hda = container_of(chip, struct hda_intel, chip);
 	struct hda_codec *codec;
 
-	if (hda->use_vga_switcheroo && !hda->need_eld_notify_link) {
+	if (hda->use_vga_switcheroo && !needs_eld_notify_link(chip)) {
 		list_for_each_codec(codec, &chip->bus)
 			codec->auto_runtime_pm = 1;
 		/* reset the power save setup */
@@ -1270,10 +1270,9 @@ static void azx_vs_gpu_bound(struct pci_dev *pci,
 {
 	struct snd_card *card = pci_get_drvdata(pci);
 	struct azx *chip = card->private_data;
-	struct hda_intel *hda = container_of(chip, struct hda_intel, chip);
 
 	if (client_id == VGA_SWITCHEROO_DIS)
-		hda->need_eld_notify_link = 0;
+		chip->bus.keep_power = 0;
 	setup_vga_switcheroo_runtime_pm(chip);
 }
 
@@ -1285,7 +1284,7 @@ static void init_vga_switcheroo(struct azx *chip)
 		dev_info(chip->card->dev,
 			 "Handle vga_switcheroo audio client\n");
 		hda->use_vga_switcheroo = 1;
-		hda->need_eld_notify_link = 1; /* cleared in gpu_bound op */
+		chip->bus.keep_power = 1; /* cleared in either gpu_bound op or codec probe */
 		chip->driver_caps |= AZX_DCAPS_PM_RUNTIME;
 		pci_dev_put(p);
 	}

sound/pci/hda/hda_intel.h

@@ -25,7 +25,6 @@ struct hda_intel {
 
 	/* vga_switcheroo setup */
 	unsigned int use_vga_switcheroo:1;
-	unsigned int need_eld_notify_link:1;
 	unsigned int vga_switcheroo_registered:1;
 	unsigned int init_failed:1; /* delayed init failed */
 

sound/pci/hda/patch_hdmi.c

@@ -2542,8 +2542,10 @@ static void generic_acomp_init(struct hda_codec *codec,
 	spec->port2pin = port2pin;
 	setup_drm_audio_ops(codec, ops);
 	if (!snd_hdac_acomp_init(&codec->bus->core, &spec->drm_audio_ops,
-				 match_bound_vga, 0))
+				 match_bound_vga, 0)) {
 		spec->acomp_registered = true;
+		codec->bus->keep_power = 0;
+	}
 }
 
 /*