ALSA: firewire-tascam: cease from delayed card registration

The delayed registration of sound card instance brings less benefit than
complication of kobject management. This commit ceases from it.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20210607081250.13397-7-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/firewire/tascam/tascam.c

@@ -90,19 +90,31 @@ static void tscm_card_free(struct snd_card *card)
 
 	snd_tscm_transaction_unregister(tscm);
 	snd_tscm_stream_destroy_duplex(tscm);
+
+	mutex_destroy(&tscm->mutex);
+	fw_unit_put(tscm->unit);
 }
 
-static void do_registration(struct work_struct *work)
+static int snd_tscm_probe(struct fw_unit *unit,
+			   const struct ieee1394_device_id *entry)
 {
-	struct snd_tscm *tscm = container_of(work, struct snd_tscm, dwork.work);
+	struct snd_card *card;
+	struct snd_tscm *tscm;
 	int err;
 
-	err = snd_card_new(&tscm->unit->device, -1, NULL, THIS_MODULE, 0,
+	err = snd_card_new(&unit->device, -1, NULL, THIS_MODULE, sizeof(*tscm), &card);
-			   &tscm->card);
 	if (err < 0)
-		return;
+		return err;
-	tscm->card->private_free = tscm_card_free;
+	card->private_free = tscm_card_free;
-	tscm->card->private_data = tscm;
+
+	tscm = card->private_data;
+	tscm->unit = fw_unit_get(unit);
+	dev_set_drvdata(&unit->device, tscm);
+	tscm->card = card;
+
+	mutex_init(&tscm->mutex);
+	spin_lock_init(&tscm->lock);
+	init_waitqueue_head(&tscm->hwdep_wait);
 
 	err = identify_model(tscm);
 	if (err < 0)
@@ -130,81 +142,33 @@ static void do_registration(struct work_struct *work)
 	if (err < 0)
 		goto error;
 
-	err = snd_card_register(tscm->card);
+	err = snd_card_register(card);
 	if (err < 0)
 		goto error;
 
-	tscm->registered = true;
-
-	return;
-error:
-	snd_card_free(tscm->card);
-	dev_info(&tscm->unit->device,
-		 "Sound card registration failed: %d\n", err);
-}
-
-static int snd_tscm_probe(struct fw_unit *unit,
-			   const struct ieee1394_device_id *entry)
-{
-	struct snd_tscm *tscm;
-
-	/* Allocate this independent of sound card instance. */
-	tscm = devm_kzalloc(&unit->device, sizeof(struct snd_tscm), GFP_KERNEL);
-	if (!tscm)
-		return -ENOMEM;
-	tscm->unit = fw_unit_get(unit);
-	dev_set_drvdata(&unit->device, tscm);
-
-	mutex_init(&tscm->mutex);
-	spin_lock_init(&tscm->lock);
-	init_waitqueue_head(&tscm->hwdep_wait);
-
-	/* Allocate and register this sound card later. */
-	INIT_DEFERRABLE_WORK(&tscm->dwork, do_registration);
-	snd_fw_schedule_registration(unit, &tscm->dwork);
-
 	return 0;
+error:
+	snd_card_free(card);
+	return err;
 }
 
 static void snd_tscm_update(struct fw_unit *unit)
 {
 	struct snd_tscm *tscm = dev_get_drvdata(&unit->device);
 
-	/* Postpone a workqueue for deferred registration. */
-	if (!tscm->registered)
-		snd_fw_schedule_registration(unit, &tscm->dwork);
-
 	snd_tscm_transaction_reregister(tscm);
 
-	/*
+	mutex_lock(&tscm->mutex);
-	 * After registration, userspace can start packet streaming, then this
+	snd_tscm_stream_update_duplex(tscm);
-	 * code block works fine.
+	mutex_unlock(&tscm->mutex);
-	 */
-	if (tscm->registered) {
-		mutex_lock(&tscm->mutex);
-		snd_tscm_stream_update_duplex(tscm);
-		mutex_unlock(&tscm->mutex);
-	}
 }
 
 static void snd_tscm_remove(struct fw_unit *unit)
 {
 	struct snd_tscm *tscm = dev_get_drvdata(&unit->device);
 
-	/*
+	// Block till all of ALSA character devices are released.
-	 * Confirm to stop the work for registration before the sound card is
+	snd_card_free(tscm->card);
-	 * going to be released. The work is not scheduled again because bus
-	 * reset handler is not called anymore.
-	 */
-	cancel_delayed_work_sync(&tscm->dwork);
-
-	if (tscm->registered) {
-		// Block till all of ALSA character devices are released.
-		snd_card_free(tscm->card);
-	}
-
-	mutex_destroy(&tscm->mutex);
-	fw_unit_put(tscm->unit);
 }
 
 static const struct ieee1394_device_id snd_tscm_id_table[] = {

sound/firewire/tascam/tascam.h

@@ -70,8 +70,6 @@ struct snd_tscm {
 	struct mutex mutex;
 	spinlock_t lock;
 
-	bool registered;
-	struct delayed_work dwork;
 	const struct snd_tscm_spec *spec;
 
 	struct fw_iso_resources tx_resources;