ALSA: hda/hdmi - Don't report spurious jack state changes

BugLink: https://bugs.launchpad.net/bugs/1848046
[ Upstream commit 551626ec0ad28dc43cae3094c35be7088cc625ab ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
index bea7b09610809f439fcf1e49b24ab6b0a10b3102..c380596b2e84c0079d7268e554dc7c645372278e 100644 (file)
--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -1421,7 +1421,7 @@ static void hdmi_pcm_reset_pin(struct hdmi_spec *spec,
 /* 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)
 {
@@ -1452,18 +1452,22 @@ static void update_eld(struct hda_codec *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
@@ -1481,6 +1485,7 @@ static void update_eld(struct hda_codec *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 */
@@ -1582,6 +1587,7 @@ static void sync_eld_via_acomp(struct hda_codec *codec,
        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);
@@ -1608,15 +1614,13 @@ static void sync_eld_via_acomp(struct hda_codec *codec,
         * 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 && eld->eld_valid) ?
+       if (changed && jack)
+               snd_jack_report(jack,
+                               (eld->monitor_present && eld->eld_valid) ?
                                SND_JACK_AVOUT : 0);
- unlock:
        mutex_unlock(&per_pin->lock);
 }