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

On Mon, 13 Jun 2016 21:51:36 +0200
Richard Cochran [off-list ref] wrote:

On Mon, Jun 13, 2016 at 01:47:13PM +0200, Richard Cochran wrote:

quoted

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