ALSA: hda: fix trigger_tstamp_latched

When the trigger_tstamp_latched flag is set, the PCM core code assumes that
the low-level driver handles the trigger timestamping itself. Ensure that
runtime->trigger_tstamp is always updated.

Buglink: alsa-project/alsa-lib#387
Reported-by: Zeno Endemann <zeno.endemann@mailbox.org>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Link: https://patch.msgid.link/20241002081306.1788405-1-perex@perex.cz
Signed-off-by: Takashi Iwai <tiwai@suse.de>

include/sound/hdaudio.h

@@ -590,7 +590,7 @@ void snd_hdac_stream_sync_trigger(struct hdac_stream *azx_dev, bool set,
 void snd_hdac_stream_sync(struct hdac_stream *azx_dev, bool start,
 			  unsigned int streams);
 void snd_hdac_stream_timecounter_init(struct hdac_stream *azx_dev,
-				      unsigned int streams);
+				      unsigned int streams, bool start);
 int snd_hdac_get_stream_stripe_ctl(struct hdac_bus *bus,
 				struct snd_pcm_substream *substream);
 

sound/hda/hdac_stream.c

@@ -664,14 +664,17 @@ static void azx_timecounter_init(struct hdac_stream *azx_dev,
  * updated accordingly, too.
  */
 void snd_hdac_stream_timecounter_init(struct hdac_stream *azx_dev,
-				      unsigned int streams)
+				      unsigned int streams, bool start)
 {
 	struct hdac_bus *bus = azx_dev->bus;
 	struct snd_pcm_runtime *runtime = azx_dev->substream->runtime;
 	struct hdac_stream *s;
 	bool inited = false;
 	u64 cycle_last = 0;
 
+	if (!start)
+		goto skip;
+
 	list_for_each_entry(s, &bus->stream_list, list) {
 		if ((streams & (1 << s->index))) {
 			azx_timecounter_init(s, inited, cycle_last);
@@ -682,6 +685,7 @@ void snd_hdac_stream_timecounter_init(struct hdac_stream *azx_dev,
 		}
 	}
 
+skip:
 	snd_pcm_gettime(runtime, &runtime->trigger_tstamp);
 	runtime->trigger_tstamp_latched = true;
 }

sound/pci/hda/hda_controller.c

@@ -275,8 +275,7 @@ static int azx_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 	spin_lock(&bus->reg_lock);
 	/* reset SYNC bits */
 	snd_hdac_stream_sync_trigger(hstr, false, sbits, sync_reg);
-	if (start)
-		snd_hdac_stream_timecounter_init(hstr, sbits);
+	snd_hdac_stream_timecounter_init(hstr, sbits, start);
 	spin_unlock(&bus->reg_lock);
 	return 0;
 }