Merge branch 'fix-iec958-unmute-on-activation' into 'master'

Fix HDMI/DisplayPort Audio by Enabling IEC958 Switches

Closes #3261

See merge request pipewire/pipewire!2556

spa/plugins/alsa/acp/acp.c

@@ -1687,6 +1687,59 @@ static int device_disable(pa_card *impl, pa_alsa_mapping *mapping, pa_alsa_devic
 	return 0;
 }
 
+/* Synchronize IEC958 digital output/input switch states.
+ *
+ * IEC958 switches default to muted in ALSA drivers. Cards with multiple
+ * HDMI/DP outputs have indexed switches (IEC958,0 IEC958,1 etc). We enable
+ * all switches since we cannot reliably map device numbers to indices.
+ */
+static void sync_iec958_controls(pa_alsa_device *d)
+{
+	snd_mixer_t *mixer_handle;
+	snd_mixer_elem_t *elem;
+	pa_card *impl;
+	int r;
+
+	mixer_handle = d->mixer_handle;
+
+	/* Pro-audio profiles don't have per-device mixers, use card mixer */
+	if (!mixer_handle) {
+		impl = d->card;
+		if (!impl || impl->card.index == ACP_INVALID_INDEX)
+			return;
+
+		mixer_handle = pa_alsa_open_mixer(impl->ucm.mixers, impl->card.index, true);
+		if (!mixer_handle)
+			return;
+	}
+
+	/* Enable all IEC958 switches */
+	for (elem = snd_mixer_first_elem(mixer_handle); elem;
+	     elem = snd_mixer_elem_next(elem)) {
+
+		if (snd_mixer_elem_get_type(elem) != SND_MIXER_ELEM_SIMPLE)
+			continue;
+
+		const char *name = snd_mixer_selem_get_name(elem);
+		if (!name || !pa_startswith(name, "IEC958"))
+			continue;
+
+		if (snd_mixer_selem_has_playback_switch(elem)) {
+			r = snd_mixer_selem_set_playback_switch_all(elem, 1);
+			if (r < 0)
+				pa_log_warn("Failed to enable IEC958 playback switch: %s",
+				           pa_alsa_strerror(r));
+		}
+
+		if (snd_mixer_selem_has_capture_switch(elem)) {
+			r = snd_mixer_selem_set_capture_switch_all(elem, 1);
+			if (r < 0)
+				pa_log_warn("Failed to enable IEC958 capture switch: %s",
+				           pa_alsa_strerror(r));
+		}
+	}
+}
+
 static int device_enable(pa_card *impl, pa_alsa_mapping *mapping, pa_alsa_device *dev)
 {
 	const char *mod_name;
@@ -1778,6 +1831,9 @@ static int device_enable(pa_card *impl, pa_alsa_mapping *mapping, pa_alsa_device
 			break;
 	}
 
+	/* Enable IEC958 switches for digital outputs */
+	sync_iec958_controls(dev);
+
 	return 0;
 }
 
@@ -2278,6 +2334,7 @@ int acp_device_set_port(struct acp_device *dev, uint32_t port_index, uint32_t fl
 			pa_sink_suspend(s, false, PA_SUSPEND_UNAVAILABLE);
 #endif
 	}
+	sync_iec958_controls(d);
 	if (impl->events && impl->events->port_changed)
 		impl->events->port_changed(impl->user_data,
 				old ? old->port.index : 0, p->port.index);