Just after appearing on IEEE 1394 bus, this unit generates several bus resets. This is due to loading firmware from on-board flash memory and initialize hardware. It's better to postpone sound card registration.
This commit applies this idea.
Signed-off-by: Takashi Sakamoto o-takashi@sakamocchi.jp --- sound/firewire/motu/motu.c | 97 ++++++++++++++++++++++++++++++++++------------ sound/firewire/motu/motu.h | 5 +++ 2 files changed, 78 insertions(+), 24 deletions(-)
diff --git a/sound/firewire/motu/motu.c b/sound/firewire/motu/motu.c index 82aae6d..d6ce4f3 100644 --- a/sound/firewire/motu/motu.c +++ b/sound/firewire/motu/motu.c @@ -38,59 +38,108 @@ static void name_card(struct snd_motu *motu) dev_name(&motu->unit->device), 100 << fw_dev->max_speed); }
-static void motu_card_free(struct snd_card *card) +static void motu_free(struct snd_motu *motu) { - struct snd_motu *motu = card->private_data; - fw_unit_put(motu->unit);
mutex_destroy(&motu->mutex); + kfree(motu); }
-static int motu_probe(struct fw_unit *unit, - const struct ieee1394_device_id *entry) +/* + * This module releases the FireWire unit data after all ALSA character devices + * are released by applications. This is for releasing stream data or finishing + * transactions safely. Thus at returning from .remove(), this module still keep + * references for the unit. + */ +static void motu_card_free(struct snd_card *card) { - struct snd_card *card; - struct snd_motu *motu; - int err; + motu_free(card->private_data); +}
- err = snd_card_new(&unit->device, -1, NULL, THIS_MODULE, - sizeof(*motu), &card); - if (err < 0) - return err; +static void do_registration(struct work_struct *work) +{ + struct snd_motu *motu = container_of(work, struct snd_motu, dwork.work); + int err;
- motu = card->private_data; - motu->card = card; - motu->unit = fw_unit_get(unit); - card->private_free = motu_card_free; + if (motu->registered) + return;
- mutex_init(&motu->mutex); + err = snd_card_new(&motu->unit->device, -1, NULL, THIS_MODULE, 0, + &motu->card); + if (err < 0) + return;
name_card(motu);
- err = snd_card_register(card); + err = snd_card_register(motu->card); if (err < 0) goto error;
+ /* + * After registered, motu instance can be released corresponding to + * releasing the sound card instance. + */ + motu->card->private_free = motu_card_free; + motu->card->private_data = motu; + motu->registered = true; + + return; +error: + snd_card_free(motu->card); + dev_info(&motu->unit->device, + "Sound card registration failed: %d\n", err); +} + +static int motu_probe(struct fw_unit *unit, + const struct ieee1394_device_id *entry) +{ + struct snd_motu *motu; + + /* Allocate this independently of sound card instance. */ + motu = kzalloc(sizeof(struct snd_motu), GFP_KERNEL); + if (motu == NULL) + return -ENOMEM; + + motu->unit = fw_unit_get(unit); dev_set_drvdata(&unit->device, motu);
+ mutex_init(&motu->mutex); + + /* Allocate and register this sound card later. */ + INIT_DEFERRABLE_WORK(&motu->dwork, do_registration); + snd_fw_schedule_registration(unit, &motu->dwork); + return 0; -error: - snd_card_free(card); - return err; }
static void motu_remove(struct fw_unit *unit) { struct snd_motu *motu = dev_get_drvdata(&unit->device);
- /* No need to wait for releasing card object in this context. */ - snd_card_free_when_closed(motu->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(&motu->dwork); + + if (motu->registered) { + /* No need to wait for releasing card object in this context. */ + snd_card_free_when_closed(motu->card); + } else { + /* Don't forget this case. */ + motu_free(motu); + } }
static void motu_bus_update(struct fw_unit *unit) { - return; + struct snd_motu *motu = dev_get_drvdata(&unit->device); + + /* Postpone a workqueue for deferred registration. */ + if (!motu->registered) + snd_fw_schedule_registration(unit, &motu->dwork); }
#define SND_MOTU_DEV_ENTRY(model, data) \ diff --git a/sound/firewire/motu/motu.h b/sound/firewire/motu/motu.h index f3d0b28..eb0ffd5 100644 --- a/sound/firewire/motu/motu.h +++ b/sound/firewire/motu/motu.h @@ -20,10 +20,15 @@ #include <sound/control.h> #include <sound/core.h>
+#include "../lib.h" + struct snd_motu { struct snd_card *card; struct fw_unit *unit; struct mutex mutex; + + bool registered; + struct delayed_work dwork; };
#endif