Re: Request for tests: scatter-gather dma support on via686 and emu10k1

[Santiago Otero <santiago@atlas.uvigo.es>]

El lun, 22-07-2002 a las 13:24, Takashi Iwai escribió:
> Hi,
> 
> At 20 Jul 2002 14:05:33 +0200,
> Santiago Otero wrote:
> > 
> > El vie, 19-07-2002 a las 19:19, Takashi Iwai escribi�:
> > > Hi,
> > > 
> > > i just added the support of scatter-gather (sg) dma support on some chips.
> > > some chips such like via686 and emu10k1 have sg dma function, which
> > > enables to use discontiguous pages as buffer.  hence we'll have almost
> > > no memory allocation problem on these chips.
> > > 
> > > on via686 and emu10k1, the playback (and capture for via686) buffers
> > > are no longer preallocated but allocated always dynamically
> > > (preallocation doesn't make sense for sg buffers).
> > > 
> > > on via686 driver, there is a new constraint.  the period byte size
> > > must be in power of two, to make sure that the period is aligned to
> > > the kernel page size.  i don't believe that this matters, though.
> > > 
> > > there are some other chips with this function, via8233, intel8x0 and
> > > trident.  they will be supported eventually soon.  (the porting must
> > > be easy but i have no hardware :)
> > > 
> > > 
> > > anyway, if you have an emu10k1 or via686 soundchip, please test the
> > > latest cvs version of alsa-kernel/alsa-driver.
> > > 
> > > 
> > I've got a via686. I've tested cvs version of alsa-driver and here are
> > my results:
> > -OSS emulation works fine
> > -xmms, mplayer, xine, ogg123 work fine
> 
> ok.  thanks for your tests.
> 
> > -all my own applications that before were working  now  sound bad. I am
> > working on the problem
> 
> this might be related with the period size restriction.
> how did you set the period size?
> please check /proc/asound/card0/pcm0p/sub0/hw_params and
> which condition is used.
> 
> 
I was using default period size. Setting period size to 1024 makes my
application work again.

Thanks.




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