[PATCH] Re: [Fwd: Re: [mythtv] Your soundcard is not reporting free space correctly.]

Ann Patterson annp322 at sbcglobal.net
Sat Mar 27 15:52:57 EST 2004


On Sat, 2004-03-27 at 12:02, Isaac Richards wrote:
> On Saturday 27 March 2004 12:22 pm, Ann Patterson wrote:
> > On Tue, 2004-03-09 at 19:32, Ann Patterson wrote:
> > > On Mon, 2004-03-08 at 08:15, Ann Patterson wrote:
> > > > After even more debugging, and a reading of the OSS docs, I discovered
> > > > that the values returned from ioctl(audio_fd, SNDCTL_DSP_GETOSPACE,
> > > > &info) are undefined if you're not writing full fragments to the card.
> > > > For every other card I tested, the values returned from this call were
> > > > fine, even when writing partial fragments. But when I ran this with the
> > > > M-Audio card, the values are all over the place. I was able to
> > > > duplicate the problem with the alsa osstest program, writing blocks of
> > > > 1000 bytes. When I changed the osstest program to write 4096 bytes
> > > > (this card's fragsize), the problem went away.
> > > >
> > > > Ann P.
> > >
> > > Here's a patch that sets the fragment size on the card to a reasonable
> > > value, then writes the audio in full fragments. It fixes the problems
> > > I'm having with the M-Audio card. I don't think it should hurt anything
> > > else.
> > >
> > > Ann P.
> >
> > I submitted this patch a couple of weeks ago, and it got ignored.
> > Recently, I've been getting emails from other people who have the same
> > card, asking when the patch is going to be applied to CVS. This (or
> > something similar) is required for this particular M-Audio card to work
> > correctly with mythtv.
> 
> I didn't apply it because it hadn't sounded like you tested it very much, and 
> there were no reports of anyone else using it, either.  As it changes 
> behavior for _everyone_, I think it needs at least a little testing before 
> going into CVS.
> 
> Isaac

If you had told me that instead of just ignoring me, I would have
attempted to get some volunteers to test, instead of waiting 3 weeks in
limbo. It's only about 10 lines of pretty straightforward code, so I
didn't think there would be a problem.

So, that said, I have tested the patch on the revo, and I can test it on
the M-Audio Audiophile (ice1712), and maybe nforce. Are there volunteers
to test on some other cards? Owners of M-Audio revolutions will thank
you.

Ann P.



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