Iwai-san,
On Mar 31 2016 08:47, Takashi Sakamoto wrote:
> When some tascam units are connected sequentially, userspace
> applications are involved at bus-reset state on IEEE 1394 bus. In the
> state, any communications can be canceled. Therefore, sound card
> registration should be delayed till the bus gets calm.
>
> This commit achieves it.
>
> Signed-off-by: Takashi Sakamoto <o-takashi@xxxxxxxxxxxxx>
> ---
> sound/firewire/tascam/tascam.c | 118 ++++++++++++++++++++++++++++-------------
> sound/firewire/tascam/tascam.h | 2 +
> 2 files changed, 84 insertions(+), 36 deletions(-)
As of today, this patch is missing in 'for-next' branch of sound.git
reporitory[1], Would you please take it again?
Regards
Takashi Sakamoto
> diff --git a/sound/firewire/tascam/tascam.c b/sound/firewire/tascam/tascam.c
> index e281c33..9dc93a7 100644
> --- a/sound/firewire/tascam/tascam.c
> +++ b/sound/firewire/tascam/tascam.c
> @@ -85,10 +85,8 @@ static int identify_model(struct snd_tscm *tscm)
> return 0;
> }
>
> -static void tscm_card_free(struct snd_card *card)
> +static void tscm_free(struct snd_tscm *tscm)
> {
> - struct snd_tscm *tscm = card->private_data;
> -
> snd_tscm_transaction_unregister(tscm);
> snd_tscm_stream_destroy_duplex(tscm);
>
> @@ -97,44 +95,36 @@ static void tscm_card_free(struct snd_card *card)
> mutex_destroy(&tscm->mutex);
> }
>
> -static int snd_tscm_probe(struct fw_unit *unit,
> - const struct ieee1394_device_id *entry)
> +static void tscm_card_free(struct snd_card *card)
> {
> - struct snd_card *card;
> - struct snd_tscm *tscm;
> + tscm_free(card->private_data);
> +}
> +
> +static void do_registration(struct work_struct *work)
> +{
> + struct snd_tscm *tscm = container_of(work, struct snd_tscm, dwork.work);
> int err;
>
> - /* create card */
> - err = snd_card_new(&unit->device, -1, NULL, THIS_MODULE,
> - sizeof(struct snd_tscm), &card);
> + err = snd_card_new(&tscm->unit->device, -1, NULL, THIS_MODULE, 0,
> + &tscm->card);
> if (err < 0)
> - return err;
> - card->private_free = tscm_card_free;
> -
> - /* initialize myself */
> - tscm = card->private_data;
> - tscm->card = card;
> - tscm->unit = fw_unit_get(unit);
> -
> - mutex_init(&tscm->mutex);
> - spin_lock_init(&tscm->lock);
> - init_waitqueue_head(&tscm->hwdep_wait);
> + return;
>
> err = identify_model(tscm);
> if (err < 0)
> goto error;
>
> - snd_tscm_proc_init(tscm);
> -
> - err = snd_tscm_stream_init_duplex(tscm);
> + err = snd_tscm_transaction_register(tscm);
> if (err < 0)
> goto error;
>
> - err = snd_tscm_create_pcm_devices(tscm);
> + err = snd_tscm_stream_init_duplex(tscm);
> if (err < 0)
> goto error;
>
> - err = snd_tscm_transaction_register(tscm);
> + snd_tscm_proc_init(tscm);
> +
> + err = snd_tscm_create_pcm_devices(tscm);
> if (err < 0)
> goto error;
>
> @@ -146,35 +136,91 @@ static int snd_tscm_probe(struct fw_unit *unit,
> if (err < 0)
> goto error;
>
> - err = snd_card_register(card);
> + err = snd_card_register(tscm->card);
> if (err < 0)
> goto error;
>
> - dev_set_drvdata(&unit->device, tscm);
> + /*
> + * After registered, tscm instance can be released corresponding to
> + * releasing the sound card instance.
> + */
> + tscm->card->private_free = tscm_card_free;
> + tscm->card->private_data = tscm;
> + tscm->registered = true;
>
> - return err;
> + return;
> error:
> - snd_card_free(card);
> - return err;
> + snd_tscm_transaction_unregister(tscm);
> + snd_tscm_stream_destroy_duplex(tscm);
> + 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 = kzalloc(sizeof(struct snd_tscm), GFP_KERNEL);
> + if (tscm == NULL)
> + return -ENOMEM;
> +
> + /* initialize myself */
> + 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;
> }
>
> 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);
> - snd_tscm_stream_update_duplex(tscm);
> - mutex_unlock(&tscm->mutex);
> + /*
> + * After registration, userspace can start packet streaming, then this
> + * code block works fine.
> + */
> + 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);
>
> - /* No need to wait for releasing card object in this context. */
> - snd_card_free_when_closed(tscm->card);
> + /*
> + * Confirm to stop the work for registration before the sound card is
> + * 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) {
> + /* No need to wait for releasing card object in this context. */
> + snd_card_free_when_closed(tscm->card);
> + } else {
> + /* Don't forget this case. */
> + tscm_free(tscm);
> + }
> }
>
> static const struct ieee1394_device_id snd_tscm_id_table[] = {
> diff --git a/sound/firewire/tascam/tascam.h b/sound/firewire/tascam/tascam.h
> index 30ab77e..1f61011 100644
> --- a/sound/firewire/tascam/tascam.h
> +++ b/sound/firewire/tascam/tascam.h
> @@ -51,6 +51,8 @@ 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;
>
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