On Sun, 20 Aug 2017 14:25:02 +0200, Takashi Sakamoto wrote: > > Hi, > > This patchset is to add support for MOTU AudioExpress. Any PCM frames and > MIDI messages are transferred in rx/tx isochronous packets. > Correspondingly, this adds an arrangement for specification flag for > position of existence flag of MIDI messages. > > I note that this unit has a quirk of acknowledge code against request > subaction on asynchronous communication. In detail, please refer to 2nd > patch of this set. To easy my development, I applied a patch to > 'firewire-ohci' module on my develop ment tree. You can see the content in > the end of this message. It's really a band-aid for the aim and can not be > merged as what it is. > > Unfortunately, current implementations of IEC 61883-1/6 packet streaming > engine is not good enough in a point to presentation timestamp, as I > reported[1]. Any plaback stream for the unit still causes periodical noise. > > [1] Status of ALSA firewire stack at Linux v4.12 development period > http://mailman.alsa-project.org/pipermail/alsa-devel/2017-April/120061.html > > -------- 8< -------- > diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c > index 8bf89267dc25..06a0906a9b56 100644 > --- a/drivers/firewire/ohci.c > +++ b/drivers/firewire/ohci.c > @@ -1499,6 +1499,10 @@ static int handle_at_packet(struct context *context, > packet->ack = evt - 0x10; > break; > > + case 0x10: > + packet->ack = ACK_PENDING; > + break; > + > case OHCI1394_evt_no_status: > if (context->flushing) { > packet->ack = RCODE_GENERATION; > -------- 8< -------- > > > Takashi Sakamoto (2): > ALSA: firewire-motu: add specification flag for position of flag for > MIDI messages > ALSA: firewire-motu: add support for MOTU Audio Express Applied both patches. Thanks. Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
