Changing hw.snd.pcm0.buffersize in 4.10.

Kevin D. Kinsey, DaleCo, S.P. kdk at daleco.biz
Mon Dec 13 10:02:54 PST 2004


Sandy Rutherford wrote:

>> Is it possible to change the sysctl variable hw.snd.pcm0.buffersize
>> (DMA buffer size for the soundcard) in FreeBSD 4.10?  I know that in
>> 5.x this is changed in devices.hints.  I'm guessing that something in
>> the kernel config file will do the job, but haven't been able to
>> figure out what.
>>
>> I am trying to increase the buffersize to get rid of little skips in
>> the playback, which I believe are caused by underruns.
>>
>> Thanks,
>> Sandy
>

} Nikolas Britton wrote:

} In FreeBSD 5.3 you can change the buffersize by adding
} hint.pcm.0.buffersize="foo" to /boot/loader.conf, have you try'ed this 
with 4.x?


I wonder if it wouldn't be:

        set hw.snd.pcm0.bufffersize=N

in accordance with other variables in /boot/loader.help.


OTOH, there was a note in

    /sys/i386/isa/sound/sound_config.h

       (as of March) that refers to using "make config"
to change the DSP_BUFFERSIZE constant during, I assume,
the kernel build operation.  As I didn't start using
FreeBSD on the desktop until 5.2 came out, I can't
say that this is in anyway authoritative, and possibly
isn't even helpful, though....

#uptime
11:57AM  up 213 days, 21:35, 1 user, load averages: 0.00, 0.00, 0.00

I think I need to go update that box ....

Kevin Kinsey


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