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

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

[Takashi Iwai]

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.


thanks,

Takashi


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

[Santiago Otero]

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

[Takashi Iwai]

At 22 Jul 2002 18:21:57 +0200,
Santiago Otero wrote:
> 
> El lun, 22-07-2002 a las 13:24, Takashi Iwai escribió:
>
> > 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.

ok, could you show me the values listed in the proc file above during
playback/record?
i guess the buffer size is not aligned to the period size, and the
number of period is relatively small.


Takashi


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

[Santiago Otero]

El mar, 23-07-2002 a las 11:21, Takashi Iwai escribió:

> 
> ok, could you show me the values listed in the proc file above during
> playback/record?
> i guess the buffer size is not aligned to the period size, and the
> number of period is relatively small.
> 

playing sound:

$cat /proc/asound/card0/pcm0p/sub0/hw_params 
access: RW_INTERLEAVED
format: S16_LE
subformat: STD
channels: 2
rate: 44100 (44100/1)
period_size: 16
buffer_size: 16384
tick_time: 10000

recording sound:

$cat /proc/asound/card0/pcm0c/sub0/hw_params
access: RW_INTERLEAVED
format: S16_LE
subformat: STD
channels: 2
rate: 44100 (44100/1)
period_size: 16
buffer_size: 16384
tick_time: 10000




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

[Takashi Iwai]

At 23 Jul 2002 19:18:53 +0200,
Santiago Otero wrote:
> 
> El mar, 23-07-2002 a las 11:21, Takashi Iwai escribi�:
> 
> > 
> > ok, could you show me the values listed in the proc file above during
> > playback/record?
> > i guess the buffer size is not aligned to the period size, and the
> > number of period is relatively small.
> > 
> 
> playing sound:
> 
> $cat /proc/asound/card0/pcm0p/sub0/hw_params 
> access: RW_INTERLEAVED
> format: S16_LE
> subformat: STD
> channels: 2
> rate: 44100 (44100/1)
> period_size: 16
> buffer_size: 16384
> tick_time: 10000

i guess you didn't set up the period size in your application
explicitly, right?
that's why it gives so small value.

on the previous driver, there was a constraint about the period and
the buffer sizes, and perhaps this increased the minimum period size
eventually.
this constraint was disabled for the time being, because this likely
conflicts with the new constraint, period size = power of two.


Takashi


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