[alsa-devel] snd_dummy on Centos - Redhat

Giovanni Maruzzelli gmaruzz.lists at gmail.com
Thu Sep 3 15:12:17 CEST 2009

On Thu, Sep 3, 2009 at 3:05 PM, Clemens Ladisch<clemens at ladisch.de> wrote:
> The interrupts of other drivers are based on the PCM stream clock, but
> the snd-dummy driver has to emulate interrupts using the system timer,
> so it is the only one affected by timer-related changes.

ok, got it

> The driver relies on the kernel's system timer.  It might be possible
> to rewrite it to use high-resolution timers, if the CentOS kernels
> supports it.

I'll have a look into it

> It would be easier to try to change the constraints of the sound card
> that snd-dummy tries to emulate; set USE_PERIODS_MIN to four or so,
> and increase period_bytes_min to some value that is at least as large
> as the numer of bytes per timer tick (with 2 channels and 16 bits at
> 48 kHz, there are 192000 bytes per second).

I'll have a look into this and then I'll report here.

Clemens, thanks for your help!


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