Sound server issue

David Wassman dmwassman at
Wed May 5 09:09:04 PDT 2004

I finally got it working using the manual settings in the LINT file. My
last question is how to configure the secondary DMA channel. The man
pages for sbc:

	The value of flags specifies the secondary DMA channel.  If the
secondary DMA channel is C, set the flags to (C | 0x10). For a sound
card without the secondary DMA channel, the flags should be set to

This is the sbc0 I am using

	device sbc0 at isa? port 0x220 irq 5 drq 1 flags 0x15

I know the settings for the card (they are set in the BIOS). It has a 8
bit channel at DMA 1 and a 16-bit at DMA 5. Am I right in guessing that
[drq 1] is the DMA designation? And then how do you get the second DMA
channel active? I think I only have 8-bit sound as wav files are
sounding pretty crappy. Am I right in thinking that the man page should
read like this:
	If the secondary DMA channel is C (where C is the number of the
DMA channel) then set the flags to (C | 0x10)

Or is C a DMA channel of some weird type?

Again thanks for the help.
David Wassman
Halcyon DIR Dive Systems
Director of Technical Services and Quality Control
Office: 1-800-425-2966 ext 315
Fax: 386-454-0815
Email: Wassman at

-----Original Message-----
From: owner-freebsd-questions at
[mailto:owner-freebsd-questions at] On Behalf Of Christian
Sent: Tuesday, May 04, 2004 6:10 PM
To: freebsd-questions at
Cc: David Wassman
Subject: Re: Sound server issue

On Tuesday 04 May 2004 07:14, David Wassman wrote:
> I have tried all that (recompile the kernel with the devices pcm and
> added) but when I type
> dmesg | grep ESS
> Nothing happens. I am going to try loading sbc manually and not PNP
and see
> if that works. Any other suggestions?

Yes David, some more suggestions:

If possible, boot your system from win to figure out irq and port
settings of 
your soundcard. Then enter the win settings into /boot/device.hints
from /usr/src/sys/conf/NOTES:

# For non-PnP cards:
device		sbc"isa"

Some DSDTs expext to find a microsoft os on your machine. in case of
this the 
tunable "hw.acpi.osname" can be set to the expexted os-name (man 4

You can use acpidump(8) to disassemble the ACPI DSDT table to ASL and
dump it 
to a file. Edit any suspect code in there and use iasl(8) to recompile
ASL to 
AML bytecode. The resulting bytecode can be loaded from userland instead
the original AML code by adding the lines  


to your /boot/loader.conf. 

Peter Schultz has written an ACPI howto, which describes step by step
how to 
fix your DSDT.


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