ALSA: hda: ext: simplify logic for stream assignment

The logic is needlessly complicated, the basic rule is:

The host streams can be found by checking the 'opened' boolean.
The link streams can be found by checking the 'link_locked' boolean.

Once a stream is found, it can be unconditionally decoupled. The
snd_hdac_ext_stream_decouple_locked() routine will make sure the
register status is modified as needed and the 'decoupled' boolean set.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Link: https://lore.kernel.org/r/20220919121041.43463-7-pierre-louis.bossart@linux.intel.comSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/hda/ext/hdac_ext_stream.c

@@ -267,19 +267,15 @@ hdac_ext_link_stream_assign(struct hdac_bus *bus,
 		if (hstream->direction != substream->stream)
 			continue;
 
-		/* check if decoupled stream and not in use is available */
-		if (hext_stream->decoupled && !hext_stream->link_locked) {
-			res = hext_stream;
-			break;
-		}
-
+		/* check if link stream is available */
 		if (!hext_stream->link_locked) {
-			snd_hdac_ext_stream_decouple_locked(bus, hext_stream, true);
 			res = hext_stream;
 			break;
 		}
+
 	}
 	if (res) {
+		snd_hdac_ext_stream_decouple_locked(bus, res, true);
 		res->link_locked = 1;
 		res->link_substream = substream;
 	}
@@ -308,13 +304,12 @@ hdac_ext_host_stream_assign(struct hdac_bus *bus,
 			continue;
 
 		if (!hstream->opened) {
-			if (!hext_stream->decoupled)
-				snd_hdac_ext_stream_decouple_locked(bus, hext_stream, true);
 			res = hext_stream;
 			break;
 		}
 	}
 	if (res) {
+		snd_hdac_ext_stream_decouple_locked(bus, res, true);
 		res->hstream.opened = 1;
 		res->hstream.running = 0;
 		res->hstream.substream = substream;