Crappy Soundchips [was Re: [Alsa-user] Re: [linux-audio-dev] ]Re: image problem...

[Werner Schweer]

On Wednesday 23 October 2002 11:51, Takashi Iwai wrote:
...
> > - SB AWE models (ugh, crap!)
> > - Yamaha YMF7xx/DS-XG (some have reported that these work ok,
> >   but in any case they have a max 3 periods limitation
> >   similar to cs4281, which can confuse apps)
>
> no, instead, the interrupts are generated in the fixed time-length,
> not at the period boundary or the end of buffer.
> thus, this chip doesn't suit for low-latency purpose at all.
>
> the similar case is ESS chips, es1968 and maestro3 (allegro).
> that is, many on-board chips on notebooks are crap, unfortunately.

it cost me a day of debugging to find out that my notebook with 
ES1983S (Maestro3i) chip does not work well with JACK. Sometimes
all seems to be ok (no underruns) sometimes timing was horrible with
lots of underruns. Tracing shows that soundcard interrupts (JACK callbacks)
sometimes are just too late.
Takashi, are you saying that this cannot be fixed because the driver
does not get an interrupt on buffer empty?

    - ws