[alsa-devel] Buffering issues 2

[Takashi Iwai]

At Sat, 3 May 2008 21:12:19 -0400,
Lee Revell wrote:
> 
> On Wed, Apr 23, 2008 at 9:18 PM, Lennart Poettering <mznyfn at 0pointer.de> wrote:
> >  The happens to be configured to 2 periods. So even if _avail_update()
> >  has some kind of period granularity (?) it should always have told us
> >  after we come back from the sleeping that at least *one* period is
> >  free. But it said 0 frames. Nada. Rien. Nichts. Kaputt.
> 
> Should we just disallow 2 periods per buffer on HDA intel?  I've never
> heard of it working for anyone on the JACK and linux audio user lists
> with less than 3.

It's actually not the number of periods.  The fact is that the DMA
position is somehow inaacurate on HD-audio hardwares.  This should be
fixed instead of a workaround.  Setting the periods to 3 doesn't
assure that any apps works.  (For JACK, a different position_fix would
work, but this may cause another problem with dmix, etc, BTW.)

The similar side-effect is found on other drivers which typically use
timer-like IRQs.


Takashi