[alsa-devel] PROBLEM: SIS7019 stops recording after 42 min

Hans Schou linux at schou.dk
Thu Jun 24 10:08:17 CEST 2010

2010/6/23 David Dillow <dave at thedillows.org>:
> On Wed, 2010-06-23 at 20:22 +0200, Hans Schou wrote:

>>    int fd = open("/dev/dsp",  O_RDWR);
>> This should not go through ALSA (I think). I gues one should use
>> something with "snd_pcm_open()" to use ALSA.
> To use ALSA directly, yes. However, there is no OSS SIS7019 driver in
> the kernel, only the ALSA one I wrote. There is an OSS emulation layer,
> so you can use the OSS API to talk to the ALSA core. Unless you are
> using a vendor (SIS/MicroJr/etc.) supplied driver, you are using ALSA in
> some capacity.

OK. Thanks for clearing it out.

I guess I should have programmed against ALSA when I started.

>> I really don't understand why I do not see this problem on other
>> hardware using the same compiled code.
> You mean the 10 second pauses during recording after 42 minutes? That is
> a driver bug, so it is specific to this card.

OK. And 42 min is also the only problem I see. I have no problems with
the recorded sounds.

> If you mean the alternating long/sort period times, then it is present
> on other hardware, but you likely don't see it either due to the
> defaults giving you more periods to work in so you don't see overruns,
> faster hardware than the SIS550 CPU, or a combination of the two. The
> bug that gives rise to the 10 second pauses can also shorten the periods
> I think, making overruns more likely to occur.



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