[alsa-devel] [PATCH 4/8] ALSA: bebob: delayed registration of sound card
Takashi Sakamoto
o-takashi at sakamocchi.jp
Thu Mar 31 01:47:05 CEST 2016
Some bebob based units tends to fail asynchronous communication when
IEEE 1394 bus is under bus-reset state. When registering sound card
instance at unit probe callback, userspace applications can be involved
to the state.
This commit postpones the registration till the bus is calm.
Signed-off-by: Takashi Sakamoto <o-takashi at sakamocchi.jp>
---
sound/firewire/bebob/bebob.c | 215 +++++++++++++++++++++++++------------------
sound/firewire/bebob/bebob.h | 5 +-
2 files changed, 131 insertions(+), 89 deletions(-)
diff --git a/sound/firewire/bebob/bebob.c b/sound/firewire/bebob/bebob.c
index 932901d..f7e2cbd 100644
--- a/sound/firewire/bebob/bebob.c
+++ b/sound/firewire/bebob/bebob.c
@@ -126,6 +126,17 @@ end:
return err;
}
+static void bebob_free(struct snd_bebob *bebob)
+{
+ snd_bebob_stream_destroy_duplex(bebob);
+ fw_unit_put(bebob->unit);
+
+ kfree(bebob->maudio_special_quirk);
+
+ mutex_destroy(&bebob->mutex);
+ kfree(bebob);
+}
+
/*
* This module releases the FireWire unit data after all ALSA character devices
* are released by applications. This is for releasing stream data or finishing
@@ -137,18 +148,11 @@ bebob_card_free(struct snd_card *card)
{
struct snd_bebob *bebob = card->private_data;
- snd_bebob_stream_destroy_duplex(bebob);
- fw_unit_put(bebob->unit);
-
- kfree(bebob->maudio_special_quirk);
-
- if (bebob->card_index >= 0) {
- mutex_lock(&devices_mutex);
- clear_bit(bebob->card_index, devices_used);
- mutex_unlock(&devices_mutex);
- }
+ mutex_lock(&devices_mutex);
+ clear_bit(bebob->card_index, devices_used);
+ mutex_unlock(&devices_mutex);
- mutex_destroy(&bebob->mutex);
+ bebob_free(card->private_data);
}
static const struct snd_bebob_spec *
@@ -176,16 +180,17 @@ check_audiophile_booted(struct fw_unit *unit)
return strncmp(name, "FW Audiophile Bootloader", 15) != 0;
}
-static int
-bebob_probe(struct fw_unit *unit,
- const struct ieee1394_device_id *entry)
+static void
+do_registration(struct work_struct *work)
{
- struct snd_card *card;
- struct snd_bebob *bebob;
- const struct snd_bebob_spec *spec;
+ struct snd_bebob *bebob =
+ container_of(work, struct snd_bebob, dwork.work);
unsigned int card_index;
int err;
+ if (bebob->registered)
+ return;
+
mutex_lock(&devices_mutex);
for (card_index = 0; card_index < SNDRV_CARDS; card_index++) {
@@ -193,64 +198,39 @@ bebob_probe(struct fw_unit *unit,
break;
}
if (card_index >= SNDRV_CARDS) {
- err = -ENOENT;
- goto end;
+ mutex_unlock(&devices_mutex);
+ return;
}
- if ((entry->vendor_id == VEN_FOCUSRITE) &&
- (entry->model_id == MODEL_FOCUSRITE_SAFFIRE_BOTH))
- spec = get_saffire_spec(unit);
- else if ((entry->vendor_id == VEN_MAUDIO1) &&
- (entry->model_id == MODEL_MAUDIO_AUDIOPHILE_BOTH) &&
- !check_audiophile_booted(unit))
- spec = NULL;
- else
- spec = (const struct snd_bebob_spec *)entry->driver_data;
-
- if (spec == NULL) {
- if ((entry->vendor_id == VEN_MAUDIO1) ||
- (entry->vendor_id == VEN_MAUDIO2))
- err = snd_bebob_maudio_load_firmware(unit);
- else
- err = -ENOSYS;
- goto end;
+ err = snd_card_new(&bebob->unit->device, index[card_index],
+ id[card_index], THIS_MODULE, 0, &bebob->card);
+ if (err < 0) {
+ mutex_unlock(&devices_mutex);
+ return;
}
- err = snd_card_new(&unit->device, index[card_index], id[card_index],
- THIS_MODULE, sizeof(struct snd_bebob), &card);
- if (err < 0)
- goto end;
- bebob = card->private_data;
- bebob->card_index = card_index;
- set_bit(card_index, devices_used);
- card->private_free = bebob_card_free;
-
- bebob->card = card;
- bebob->unit = fw_unit_get(unit);
- bebob->spec = spec;
- mutex_init(&bebob->mutex);
- spin_lock_init(&bebob->lock);
- init_waitqueue_head(&bebob->hwdep_wait);
-
err = name_device(bebob);
if (err < 0)
goto error;
- if ((entry->vendor_id == VEN_MAUDIO1) &&
- (entry->model_id == MODEL_MAUDIO_FW1814))
- err = snd_bebob_maudio_special_discover(bebob, true);
- else if ((entry->vendor_id == VEN_MAUDIO1) &&
- (entry->model_id == MODEL_MAUDIO_PROJECTMIX))
- err = snd_bebob_maudio_special_discover(bebob, false);
- else
+ if (bebob->spec == &maudio_special_spec) {
+ if (bebob->entry->model_id == MODEL_MAUDIO_FW1814)
+ err = snd_bebob_maudio_special_discover(bebob, true);
+ else
+ err = snd_bebob_maudio_special_discover(bebob, false);
+ } else {
err = snd_bebob_stream_discover(bebob);
+ }
+ if (err < 0)
+ goto error;
+
+ err = snd_bebob_stream_init_duplex(bebob);
if (err < 0)
goto error;
snd_bebob_proc_init(bebob);
- if ((bebob->midi_input_ports > 0) ||
- (bebob->midi_output_ports > 0)) {
+ if (bebob->midi_input_ports > 0 || bebob->midi_output_ports > 0) {
err = snd_bebob_create_midi_devices(bebob);
if (err < 0)
goto error;
@@ -264,16 +244,75 @@ bebob_probe(struct fw_unit *unit,
if (err < 0)
goto error;
- err = snd_bebob_stream_init_duplex(bebob);
+ err = snd_card_register(bebob->card);
if (err < 0)
goto error;
- if (!bebob->maudio_special_quirk) {
- err = snd_card_register(card);
- if (err < 0) {
- snd_bebob_stream_destroy_duplex(bebob);
- goto error;
- }
+ set_bit(card_index, devices_used);
+ mutex_unlock(&devices_mutex);
+
+ /*
+ * After registered, bebob instance can be released corresponding to
+ * releasing the sound card instance.
+ */
+ bebob->card->private_free = bebob_card_free;
+ bebob->card->private_data = bebob;
+ bebob->registered = true;
+
+ return;
+error:
+ mutex_unlock(&devices_mutex);
+ snd_bebob_stream_destroy_duplex(bebob);
+ snd_card_free(bebob->card);
+ dev_info(&bebob->unit->device,
+ "Sound card registration failed: %d\n", err);
+}
+
+static int
+bebob_probe(struct fw_unit *unit, const struct ieee1394_device_id *entry)
+{
+ struct snd_bebob *bebob;
+ const struct snd_bebob_spec *spec;
+
+ if (entry->vendor_id == VEN_FOCUSRITE &&
+ entry->model_id == MODEL_FOCUSRITE_SAFFIRE_BOTH)
+ spec = get_saffire_spec(unit);
+ else if (entry->vendor_id == VEN_MAUDIO1 &&
+ entry->model_id == MODEL_MAUDIO_AUDIOPHILE_BOTH &&
+ !check_audiophile_booted(unit))
+ spec = NULL;
+ else
+ spec = (const struct snd_bebob_spec *)entry->driver_data;
+
+ if (spec == NULL) {
+ if (entry->vendor_id == VEN_MAUDIO1 ||
+ entry->vendor_id == VEN_MAUDIO2)
+ return snd_bebob_maudio_load_firmware(unit);
+ else
+ return -ENODEV;
+ }
+
+ /* Allocate this independent of sound card instance. */
+ bebob = kzalloc(sizeof(struct snd_bebob), GFP_KERNEL);
+ if (bebob == NULL)
+ return -ENOMEM;
+
+ bebob->unit = fw_unit_get(unit);
+ bebob->entry = entry;
+ bebob->spec = spec;
+ dev_set_drvdata(&unit->device, bebob);
+
+ mutex_init(&bebob->mutex);
+ spin_lock_init(&bebob->lock);
+ init_waitqueue_head(&bebob->hwdep_wait);
+
+ /* Allocate and register this sound card later. */
+ INIT_DEFERRABLE_WORK(&bebob->dwork, do_registration);
+
+ if (entry->vendor_id != VEN_MAUDIO1 ||
+ (entry->model_id != MODEL_MAUDIO_FW1814 &&
+ entry->model_id != MODEL_MAUDIO_PROJECTMIX)) {
+ snd_fw_schedule_registration(unit, &bebob->dwork);
} else {
/*
* This is a workaround. This bus reset seems to have an effect
@@ -285,19 +324,11 @@ bebob_probe(struct fw_unit *unit,
* signals from dbus and starts I/Os. To avoid I/Os till the
* future bus reset, registration is done in next update().
*/
- bebob->deferred_registration = true;
fw_schedule_bus_reset(fw_parent_device(bebob->unit)->card,
false, true);
}
- dev_set_drvdata(&unit->device, bebob);
-end:
- mutex_unlock(&devices_mutex);
- return err;
-error:
- mutex_unlock(&devices_mutex);
- snd_card_free(card);
- return err;
+ return 0;
}
/*
@@ -324,15 +355,11 @@ bebob_update(struct fw_unit *unit)
if (bebob == NULL)
return;
- fcp_bus_reset(bebob->unit);
-
- if (bebob->deferred_registration) {
- if (snd_card_register(bebob->card) < 0) {
- snd_bebob_stream_destroy_duplex(bebob);
- snd_card_free(bebob->card);
- }
- bebob->deferred_registration = false;
- }
+ /* Postpone a workqueue for deferred registration. */
+ if (!bebob->registered)
+ snd_fw_schedule_registration(unit, &bebob->dwork);
+ else
+ fcp_bus_reset(bebob->unit);
}
static void bebob_remove(struct fw_unit *unit)
@@ -342,8 +369,20 @@ static void bebob_remove(struct fw_unit *unit)
if (bebob == NULL)
return;
- /* No need to wait for releasing card object in this context. */
- snd_card_free_when_closed(bebob->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(&bebob->dwork);
+
+ if (bebob->registered) {
+ /* No need to wait for releasing card object in this context. */
+ snd_card_free_when_closed(bebob->card);
+ } else {
+ /* Don't forget this case. */
+ bebob_free(bebob);
+ }
}
static const struct snd_bebob_rate_spec normal_rate_spec = {
diff --git a/sound/firewire/bebob/bebob.h b/sound/firewire/bebob/bebob.h
index b50bb33d..2a442a7 100644
--- a/sound/firewire/bebob/bebob.h
+++ b/sound/firewire/bebob/bebob.h
@@ -83,6 +83,10 @@ struct snd_bebob {
struct mutex mutex;
spinlock_t lock;
+ bool registered;
+ struct delayed_work dwork;
+
+ const struct ieee1394_device_id *entry;
const struct snd_bebob_spec *spec;
unsigned int midi_input_ports;
@@ -111,7 +115,6 @@ struct snd_bebob {
/* for M-Audio special devices */
void *maudio_special_quirk;
- bool deferred_registration;
/* For BeBoB version quirk. */
unsigned int version;
--
2.7.4
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