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ALSA: firewire-lib: record cycle count for the first packet
authorTakashi Sakamoto <o-takashi@sakamocchi.jp>
Wed, 22 Mar 2017 12:30:15 +0000 (21:30 +0900)
committerTakashi Iwai <tiwai@suse.de>
Tue, 28 Mar 2017 10:33:24 +0000 (12:33 +0200)
commita04513f8b1980e7ddd9082461aceaf8b3e8f4981
treecacb1f98f5650c58664294310d76119362695285
parent59f6482c2183fc3b3e42e0e2ae83a347ee6346c5
ALSA: firewire-lib: record cycle count for the first packet

Currently, packet streaming layer passes generated SYT value to data block
processing layer. However, this is not enough in a case that the data block
processing layer generates time stamps by its own ways.

For out-packet stream, the packet streaming layer guarantees 8,000 times
calls of data block processing layers per sec. Therefore, when cycle count
of the first packet is recorded, data block processing layers can calculate
own time stamps with the recorded value.

For the reason, this commit allows packet streaming layer to record the
first cycle count. Each data block processing layer can read the count by
accessing a member of structure for packet streaming layer.

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