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| author | Takashi Sakamoto <o-takashi@sakamocchi.jp> | 2014-04-25 22:45:30 +0900 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2014-05-26 14:33:10 +0200 |
| commit | 9b1ee0b2cb8bffdbb3003b1d5205f3ae0592c15a (patch) | |
| tree | 31124c27fddbaca390e63ebb47174ade02952a89 /sound/firewire | |
| parent | a2b2a7798fb6a5c639189e5c8f608a56fdc7a222 (diff) | |
| download | lwn-9b1ee0b2cb8bffdbb3003b1d5205f3ae0592c15a.tar.gz lwn-9b1ee0b2cb8bffdbb3003b1d5205f3ae0592c15a.zip | |
ALSA: firewire/bebob: Add a workaround for M-Audio special Firewire series
In post commit, a quirk of this firmware about transactions is reported.
This commit apply a workaround for this quirk.
They often fail transactions due to gap_count mismatch. This state is changed
by generating bus reset.
The fw_schedule_bus_reset() is an exported symbol in firewire-core. But there
are no header for public. This commit moves its prototype from
drivers/firewire/core.h to include/linux/firewire.h.
This mismatch still affects bus management before generating this bus reset.
It still takes a time to call driver's probe() because transactions are still
often failed.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/firewire')
| -rw-r--r-- | sound/firewire/bebob/bebob.c | 32 | ||||
| -rw-r--r-- | sound/firewire/bebob/bebob.h | 1 |
2 files changed, 29 insertions, 4 deletions
diff --git a/sound/firewire/bebob/bebob.c b/sound/firewire/bebob/bebob.c index e1dd4219ea6c..31b96b7264cf 100644 --- a/sound/firewire/bebob/bebob.c +++ b/sound/firewire/bebob/bebob.c @@ -247,10 +247,26 @@ bebob_probe(struct fw_unit *unit, if (err < 0) goto error; - err = snd_card_register(card); - if (err < 0) { - snd_bebob_stream_destroy_duplex(bebob); - goto error; + if (!bebob->maudio_special_quirk) { + err = snd_card_register(card); + if (err < 0) { + snd_bebob_stream_destroy_duplex(bebob); + goto error; + } + } else { + /* + * This is a workaround. This bus reset seems to have an effect + * to make devices correctly handling transactions. Without + * this, the devices have gap_count mismatch. This causes much + * failure of transaction. + * + * Just after registration, user-land application receive + * 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); @@ -273,6 +289,14 @@ bebob_update(struct fw_unit *unit) fcp_bus_reset(bebob->unit); snd_bebob_stream_update_duplex(bebob); + + 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; + } } static void bebob_remove(struct fw_unit *unit) diff --git a/sound/firewire/bebob/bebob.h b/sound/firewire/bebob/bebob.h index 4a54e746c5c6..91b26b0c649a 100644 --- a/sound/firewire/bebob/bebob.h +++ b/sound/firewire/bebob/bebob.h @@ -109,6 +109,7 @@ struct snd_bebob { /* for M-Audio special devices */ void *maudio_special_quirk; + bool deferred_registration; }; static inline int |