[LAD] Writing an IEEE 802.1BA (AVB) compliant network backend for Jack2

[Adrian Knoth]

On Tue, Apr 05, 2011 at 08:29:03AM -0700, Stephen Hemminger wrote:

Just a full quote for the list, I guess Stephen's mail hasn't reached
anyone but me due to subscribers-only policy on LAD.

> > On 04/05/11 11:53, Christoph Kuhr wrote:
> > 
> > Hi!
> > 
> > > apparently the ASUS 890FX mainboard has a yukon 88e8059 nic, which i
> > > have not verified yet.
> > 
> > To be precise, it's only the Crosshair IV Formular 890FX, all others
> > either have Realtek or Intel.
> > 
> > > the marvell yukon 88e8059 specs say this nic is avb ready.
> > 
> > Indeed, at least if we believe the little PDF provided by Marvell.
> > 
> > I don't know exactly what this means, it seems they support multiple
> > RX/TX queues, so AVB packages might end up in a priority lane while bulk
> > traffic is handled via a different queue.
> 
> It has 2 Tx queues, but one is not used because it really doesn't
> offer any benefit. The sync Tx queue doesn't fit the Linux
> multiple Tx queue model.
> 
> > They also support hardware timestamping. The Linux driver in question is
> > sky2, in sky2.h, they already have some PTP related defines, but the
> > sky2.c doesn't make use of them.
> 
> The hardware timestamping is also disabled in Linux for a couple
> of reasons. First the wraparound of the timestamp is not well
> documented, but more importantly timestamping and RSS hash can
> not be combined and RSS hash seemed more useful.

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