ALSA: dice: update isochronous resources when starting packet streaming after bus...
authorTakashi Sakamoto <o-takashi@sakamocchi.jp>
Tue, 11 Jun 2019 13:21:17 +0000 (22:21 +0900)
committerTakashi Iwai <tiwai@suse.de>
Tue, 11 Jun 2019 14:02:10 +0000 (16:02 +0200)
commitd5553026b53a246861d00221a6beb3674a30df03
tree32f7ad60c76466cb655aace443a8b96688aa186d
parent3cd2c2d780a23e8b847c9ec22e8bc9dd6e685cbe
ALSA: dice: update isochronous resources when starting packet streaming after bus-reset

After bus reset, isochronous resource manager releases all of allocated
isochronous resources. The nodes to transfer isochronous packet should
request reallocation of the resources.

However, between the bus-reset and invocation of 'struct fw_driver.update'
handler, ALSA PCM application can detect this situation by XRUN because
the target device cancelled to transmit packets once bus-reset occurs.

Due to the above mechanism, ALSA fireface driver just stops packet
streaming in the update handler, thus pcm.prepare handler should
request the reallocation.

This commit requests the reallocation in pcm.prepare callback when
bus generation is changed.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
sound/firewire/dice/dice-stream.c