Changing hw.snd.pcm0.buffersize in 4.10.

[Nikolas Britton]

Christian Hiris wrote:

>AFAIK the define is named DSP_BUFFSIZE (in src/sys/dev/sound/pcm/sound.h. 
>DSP_BUFFSIZE can be used to define the default buffersize for sound drivers, 
>but most of the sound drivers use their own defines.
>
>If you want to change the default buffersize for a sound driver you need to 
>search for a define like xxx_BUFFSIZE, where xxx is the name of the sound 
>driver (maybe some developers use other naming-conventions).
>
>ie., if you want to change the default buffersize of the ESS driver you need 
>to change the line "#define ESS_BUFFSIZE (4096)" in 
>src/sys/dev/sound/isa/ess.c.
>
>If you use the sbc driver, you need to do this changes in sb8.c or sb16.c, 
>depending on the soundcard you are using. sbc.c is only the code for the 
>corresponding bridge driver.
>
>However, I'm not a guru, so I can't guess, if a driver works better with any 
>other buffer size defined, than the original one. 
>
>  
>
Yes, This Worked!

stumbleine# pwd
/usr/src/sys/dev/sound/isa

stumbleine# diff ess.c ess.bak
41c41
< #define ESS_BUFFSIZE (8192)
---
 > #define ESS_BUFFSIZE (4096)

stumbleine# diff sb16.c sb16.bak
41c41
< #define SB16_BUFFSIZE    8192
---
 > #define SB16_BUFFSIZE    4096

Kernel Config file:
options        PNPBIOS
device        pcm        # Generic Sound Support
device         sbc0 at isa? port 0x220 irq 10 drq 1

stumbleine# dmesg | grep ESS
sbc0: <ESS 1688> at port 0x220-0x22f irq 10 drq 1 on isa0
pcm0: <ESS 18xx DSP> on sbc0

stumbleine# sysctl hw.snd
hw.snd.targetirqrate: 32
hw.snd.report_soft_formats: 1
hw.snd.verbose: 1
hw.snd.maxautovchans: 0
hw.snd.pcm0.buffersize: 8192
hw.snd.pcm0.vchans: 0

stumbleine# uname -a
FreeBSD stumbleine.intranet 4.10-STABLE FreeBSD 4.10-STABLE #3: Tue Dec 
14 23:40:48 CST 2004     
root at stumbleine.intranet:/usr/src/sys/compile/STUMBLEINE  i386