ALSA: oxfw: don't add MIDI/PCM interface when packet streaming is unavailable

Stanton SCS.1d doesn't support packet streaming even if it has plugs for
isochronous communication.

This commit is a preparation for this case. The 'has_input' member is
added to specific structure, and MIDI/PCM interfaces are not added when
the member is false.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20200113073418.24622-3-o-takashi@sakamocchi.jpSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/firewire/oxfw/oxfw-stream.c

@@ -772,6 +772,8 @@ int snd_oxfw_stream_discover(struct snd_oxfw *oxfw)
 			if (formation.midi > 0)
 				oxfw->midi_output_ports = 1;
 		}
+
+		oxfw->has_input = true;
 	}
 end:
 	return err;

sound/firewire/oxfw/oxfw.c

@@ -118,6 +118,7 @@ static void oxfw_card_free(struct snd_card *card)
 {
 	struct snd_oxfw *oxfw = card->private_data;
 
+	if (oxfw->has_output || oxfw->has_input)
 		snd_oxfw_stream_destroy_duplex(oxfw);
 }
 
@@ -206,6 +207,7 @@ static void do_registration(struct work_struct *work)
 	if (err < 0)
 		goto error;
 
+	if (oxfw->has_output || oxfw->has_input) {
 		err = snd_oxfw_stream_init_duplex(oxfw);
 		if (err < 0)
 			goto error;
@@ -223,6 +225,7 @@ static void do_registration(struct work_struct *work)
 		err = snd_oxfw_create_hwdep(oxfw);
 		if (err < 0)
 			goto error;
+	}
 
 	err = snd_card_register(oxfw->card);
 	if (err < 0)
@@ -274,9 +277,11 @@ static void oxfw_bus_reset(struct fw_unit *unit)
 	fcp_bus_reset(oxfw->unit);
 
 	if (oxfw->registered) {
+		if (oxfw->has_output || oxfw->has_input) {
 			mutex_lock(&oxfw->mutex);
 			snd_oxfw_stream_update_duplex(oxfw);
 			mutex_unlock(&oxfw->mutex);
+		}
 
 		if (oxfw->entry->vendor_id == OUI_STANTON)
 			snd_oxfw_scs1x_update(oxfw);

sound/firewire/oxfw/oxfw.h

@@ -45,6 +45,7 @@ struct snd_oxfw {
 
 	bool wrong_dbs;
 	bool has_output;
+	bool has_input;
 	u8 *tx_stream_formats[SND_OXFW_STREAM_FORMAT_ENTRIES];
 	u8 *rx_stream_formats[SND_OXFW_STREAM_FORMAT_ENTRIES];
 	bool assumed;