From 551626ec0ad28dc43cae3094c35be7088cc625ab Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai@suse.de>
Date: Wed, 17 Jul 2019 14:30:23 +0200
Subject: [PATCH] ALSA: hda/hdmi - Don't report spurious jack state changes
Git-commit: 551626ec0ad28dc43cae3094c35be7088cc625ab
Patch-mainline: v5.4-rc1
References: bsc#1051510

The HDMI jack handling reports the state change always via
snd_jack_report() whenever hdmi_present_sense() is called, even if the
state itself doesn't change from the previous time.  This is mostly
harmless but still a bit confusing to user-space.

This patch reduces such spurious jack state changes and reports only
when the state really changed.  Also, as a minor optimization, avoid
overwriting the pin ELD data when the state is identical.

Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

---
 sound/pci/hda/patch_hdmi.c |   33 +++++++++++++++++++--------------
 1 file changed, 19 insertions(+), 14 deletions(-)

--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -1434,7 +1434,7 @@ static void hdmi_pcm_reset_pin(struct hd
 /* update per_pin ELD from the given new ELD;
  * setup info frame and notification accordingly
  */
-static void update_eld(struct hda_codec *codec,
+static bool update_eld(struct hda_codec *codec,
 		       struct hdmi_spec_per_pin *per_pin,
 		       struct hdmi_eld *eld)
 {
@@ -1465,18 +1465,22 @@ static void update_eld(struct hda_codec
 		snd_hdmi_show_eld(codec, &eld->info);
 
 	eld_changed = (pin_eld->eld_valid != eld->eld_valid);
-	if (eld->eld_valid && pin_eld->eld_valid)
+	eld_changed |= (pin_eld->monitor_present != eld->monitor_present);
+	if (!eld_changed && eld->eld_valid && pin_eld->eld_valid)
 		if (pin_eld->eld_size != eld->eld_size ||
 		    memcmp(pin_eld->eld_buffer, eld->eld_buffer,
 			   eld->eld_size) != 0)
 			eld_changed = true;
 
-	pin_eld->monitor_present = eld->monitor_present;
-	pin_eld->eld_valid = eld->eld_valid;
-	pin_eld->eld_size = eld->eld_size;
-	if (eld->eld_valid)
-		memcpy(pin_eld->eld_buffer, eld->eld_buffer, eld->eld_size);
-	pin_eld->info = eld->info;
+	if (eld_changed) {
+		pin_eld->monitor_present = eld->monitor_present;
+		pin_eld->eld_valid = eld->eld_valid;
+		pin_eld->eld_size = eld->eld_size;
+		if (eld->eld_valid)
+			memcpy(pin_eld->eld_buffer, eld->eld_buffer,
+			       eld->eld_size);
+		pin_eld->info = eld->info;
+	}
 
 	/*
 	 * Re-setup pin and infoframe. This is needed e.g. when
@@ -1494,6 +1498,7 @@ static void update_eld(struct hda_codec
 			       SNDRV_CTL_EVENT_MASK_VALUE |
 			       SNDRV_CTL_EVENT_MASK_INFO,
 			       &get_hdmi_pcm(spec, pcm_idx)->eld_ctl->id);
+	return eld_changed;
 }
 
 /* update ELD and jack state via HD-audio verbs */
@@ -1595,6 +1600,7 @@ static void sync_eld_via_acomp(struct hd
 	struct hdmi_spec *spec = codec->spec;
 	struct hdmi_eld *eld = &spec->temp_eld;
 	struct snd_jack *jack = NULL;
+	bool changed;
 	int size;
 
 	mutex_lock(&per_pin->lock);
@@ -1621,14 +1627,13 @@ static void sync_eld_via_acomp(struct hd
 	 * disconnected event. Jack must be fetched before update_eld()
 	 */
 	jack = pin_idx_to_jack(codec, per_pin);
-	update_eld(codec, per_pin, eld);
+	changed = update_eld(codec, per_pin, eld);
 	if (jack == NULL)
 		jack = pin_idx_to_jack(codec, per_pin);
-	if (jack == NULL)
-		goto unlock;
-	snd_jack_report(jack,
-			eld->monitor_present ? SND_JACK_AVOUT : 0);
- unlock:
+	if (changed && jack)
+		snd_jack_report(jack,
+				(eld->monitor_present && eld->eld_valid) ?
+				SND_JACK_AVOUT : 0);
 	mutex_unlock(&per_pin->lock);
 }