Re: [Protux-devel] more on RTC

[Luciano Giordana]

> I had the same problem, that audio playback/record was very sensitive for
> xruns/dropouts.
>
> So I tried the development kernel, (which is I found stable enough) to see
> if it worked (the low latency patch is integrated in 2.6.0-test_x as you
> may know), but the real problem (in my case) was IRQ sharing.
>
> My soundcard is REALY IRQ hungry, and even moving some windows or let a
> window popup did disturb the sound.
>
> So I looked which IRQ my soundcard was using (lspci -vvv), and it was
> number 9.
> The same IRQ for my usb, network card, ide controller etc :-)
>
> It's know using IRQ 5, and no dropouts at all, only a few xrun's (xruns
> are detected by: "can't read from bus" errors, isn't it??) (I'm using
> fps=20)

This is a good tip, I will check myself my IRQ conditions.

xruns are being reported as warning in current cvs code. Also, fps
are being setted as default (10) for a while. I will fix to set in by global 
properties window,
and/or read it from protuxrc again. But now, remeber, each bus has its own fps 
setting. 

I already added the real time scheduler activation in MADM::init, but it only 
works if
you run protux as root. it worth a try, since I noticed a good reduction on 
xruns.
But the low latency is critical in this sense, surely.

> There's also a project "Demudi" which goal is to make a sound related
> distribution (debian as it's bases), and one of the primary goals was: low
> latency!
> They probably know also a bit more about this topic.

I new about it, and Reinhard already request protux inclusion on this distro.

[]s