Kirkwood SoC - AVB support questions ..?

Kirkwood SoC - AVB support questions ..?

[errordeveloper]

Hello dear ALSA developer list members,

I have a question regarding hardware features of Marvell Kirkwood chip.

I is known that the NIC core on the chip includes support for Ethernet
AV Bridging, which is still a draft standard ..but i suppose that
Marvell released this chip with quite functional AVB implementation.

grepping the sk98 driver code actually shows numerous lines with AVB as
well as PTP, so i suppose they have implemented IOCTL in the sk98 driver
..i'm still doubtfull about Linux kernel PTP implementation ..is there
now in some form or not?

Did any of you have a look at AVB ?
how do you think the driver for it could fit into Linux Netdev and ALSA?

How are the CobraNet and EtherSound drivers designed, has anyone used
those cards ?? (one was from DigiGram and another from Audio Science IIRC)


Regards,
-- 
Ilya Dmitrichenko 

Re: Kirkwood SoC - AVB support questions ..?

[Eliot Blennerhassett]

On 10/07/10 08:01, errordeveloper@gmail.com wrote:

> How are the CobraNet and EtherSound drivers designed, has anyone used
> those cards ?? (one was from DigiGram and another from Audio Science IIRC)

AudioScience ASI6416 and AS6316 cards use cobranet processor from
Cirrus, and appear to the host as a standard soundcard.

Similarly, ASI6585 uses hardware implementation of Axia livewire protocol.

So, none of the network audio protocol is handled by the host PC.


-- 
Eliot Blennerhassett
AudioScience Inc.

Re: Kirkwood SoC - AVB support questions ..?

[errordeveloper]

Ok, so it's really no wonder about these,
those proprietary are hendeled transparently by an ASIC or an FPGA.

so this won't be the case with AVB,
i suppose at low sampling (48k or 44k1) it will work over a regular
network, provided the host is doing only AVB streaming and there is
no other trafic on the network.
I'm not intery sure how stream reservation would work, but may be
you can fake it in software somehow.

there is PTP driver patch here:
http://kerneltrap.org/mailarchive/linux-netdev/2010/4/29/6276033

it seems to be ptpv1 ..hm
this ptpd list thread is about patents:
http://lists.infradead.org/pipermail/ptpd/2010-January/000023.html

could these patents be such a problem?
will AVB support have to be distributed trough patches because of this?


well ..i haven't used Netjack or anything, so cannot tell.

On Sat, Jul 10, 2010 at 08:15:51PM +1200, Eliot Blennerhassett wrote:
> On 10/07/10 08:01, errordeveloper@gmail.com wrote:
> 
> > How are the CobraNet and EtherSound drivers designed, has anyone used
> > those cards ?? (one was from DigiGram and another from Audio Science IIRC)
> 
> AudioScience ASI6416 and AS6316 cards use cobranet processor from
> Cirrus, and appear to the host as a standard soundcard.
> 
> Similarly, ASI6585 uses hardware implementation of Axia livewire protocol.
> 
> So, none of the network audio protocol is handled by the host PC.
> 
> 
> -- 
> Eliot Blennerhassett
> AudioScience Inc.