Re: [very-RFC 0/8] TSN driver for the kernel

One Thousand Gnomes
2016-06-14T11:18:54Z

On Mon, 13 Jun 2016 21:51:36 +0200
Richard Cochran <richardcochran@gmail.com> wrote:

> On Mon, Jun 13, 2016 at 01:47:13PM +0200, Richard Cochran wrote:
> > 3. ALSA support for tunable AD/DA clocks. The rate of the Listener's
> > DA clock must match that of the Talker and the other Listeners.
> > Either you adjust it in HW using a VCO or similar, or you do
> > adaptive sample rate conversion in the application. (And that is
> > another reason for *not* having a shared kernel buffer.) For the
> > Talker, either you adjust the AD clock to match the PTP time, or
> > you measure the frequency offset.
>
> Actually, we already have support for tunable clock-like HW elements,
> namely the dynamic posix clock API. It is trivial to write a driver
> for VCO or the like. I am just not too familiar with the latest high
> end audio devices.

Why high end ? Even the most basic USB audio is frame based and
isosynchronous to the USB clock. It also reports back the delay
properties.

Alan