It seems that my notebook (HP nx7400) also doesn't have sound support
with same problem conditions. I also installed 4.1-release and tried
to upgrade to 4.2-current (snapshot from 5 Aug 2007) but no results.
Here is my dmesg:
$ dmesg
OpenBSD 4.2-beta (GENERIC) #1: Sun Aug  5 19:58:43 EEST 2007
    root@mg42:/data0/share/OpenBSD/src/sys/arch/i386/compile/GENERIC
cpu0: Intel(R) Celeron(R) M CPU 430 @ 1.73GHz ("GenuineIntel" 686-class) 1.73 GH
z
cpu0: FPU,V86,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,CFLUSH,D
S,ACPI,MMX,FXSR,SSE,SSE2,SS,TM,SBF,SSE3,MWAIT,TM2,xTPR
real mem  = 527855616 (503MB)
avail mem = 502767616 (479MB)
mainbus0 at root
bios0 at mainbus0: AT/286+ BIOS, date 10/23/06, BIOS32 rev. 0 @ 0xf0000, SMBIOS
rev. 2.4 @ 0xf3f1c (23 entries)
bios0: Hewlett-Packard HP Compaq nx7400 (EY587ES#ACB)
pcibios0 at bios0: rev 2.1 @ 0xf0000/0x2000
pcibios0: PCI IRQ Routing Table rev 1.0 @ 0xf07c0/192 (10 entries)
pcibios0: bad IRQ table checksum
pcibios0: PCI IRQ Routing Table rev 1.0 @ 0xff880/192 (10 entries)
pcibios0: PCI Exclusive IRQs: 5 10 11
pcibios0: PCI Interrupt Router at 000:31:0 ("Intel 82801FBM LPC" rev 0x00)
pcibios0: PCI bus #16 is the last bus
bios0: ROM list: 0xc0000/0x10000!
acpi at mainbus0 not configured
cpu0 at mainbus0
pci0 at mainbus0 bus 0: configuration mode 1 (no bios)
pchb0 at pci0 dev 0 function 0 "Intel 82945GM MCH" rev 0x03
vga1 at pci0 dev 2 function 0 "Intel 82945GM Video" rev 0x03: aperture at 0xf440
0000, size 0x10000000
wsdisplay0 at vga1 mux 1: console (80x25, vt100 emulation)
wsdisplay0: screen 1-5 added (80x25, vt100 emulation)
"Intel 82945GM Video" rev 0x03 at pci0 dev 2 function 1 not configured
azalia0 at pci0 dev 27 function 0 "Intel 82801GB HD Audio" rev 0x01: irq 10
azalia0: host: High Definition Audio rev. 1.0
azalia0: codec: Analog Devices AD1981HD (rev. 2.0), HDA version 1.0
azalia0: codec: AT&T/Lucent/0x3026 (rev. 7.0), HDA version 1.0
azalia0: codec[1]: No support for modem function groups
azalia0: codec[1]: No audio function groups
audio0 at azalia0
ppb0 at pci0 dev 28 function 0 "Intel 82801GB PCIE" rev 0x01
pci1 at ppb0 bus 8
ppb1 at pci0 dev 28 function 1 "Intel 82801GB PCIE" rev 0x01
pci2 at ppb1 bus 16
"Broadcom BCM4311" rev 0x01 at pci2 dev 0 function 0 not configured
uhci0 at pci0 dev 29 function 0 "Intel 82801GB USB" rev 0x01: irq 10
uhci1 at pci0 dev 29 function 1 "Intel 82801GB USB" rev 0x01: irq 11
uhci2 at pci0 dev 29 function 2 "Intel 82801GB USB" rev 0x01: irq 11
uhci3 at pci0 dev 29 function 3 "Intel 82801GB USB" rev 0x01: irq 10
ehci0 at pci0 dev 29 function 7 "Intel 82801GB USB" rev 0x01: irq 10
usb0 at ehci0: USB revision 2.0
uhub0 at usb0: Intel EHCI root hub, rev 2.00/1.00, addr 1
ppb2 at pci0 dev 30 function 0 "Intel 82801BAM Hub-to-PCI" rev 0xe1
pci3 at ppb2 bus 2
cbb0 at pci3 dev 6 function 0 "TI PCIXX12 CardBus" rev 0x00: irq 11
bce0 at pci3 dev 14 function 0 "Broadcom BCM4401B1" rev 0x02: irq 10, address 00
:17:08:47:c0:ed
bmtphy0 at bce0 phy 1: BCM4401 10/100baseTX PHY, rev. 0
cardslot0 at cbb0 slot 0 flags 0
cardbus0 at cardslot0: bus 3 device 0 cacheline 0x10, lattimer 0x20
pcmcia0 at cardslot0
ichpcib0 at pci0 dev 31 function 0 "Intel 82801GBM LPC" rev 0x01: PM disabled
pciide0 at pci0 dev 31 function 1 "Intel 82801GB IDE" rev 0x01: DMA, channel 0 c
onfigured to compatibility, channel 1 configured to compatibility
atapiscsi0 at pciide0 channel 0 drive 0
scsibus0 at atapiscsi0: 2 targets
cd0 at scsibus0 targ 0 lun 0: <HL-DT-ST, DVDRAM GSA-T10N, PC05> SCSI0 5/cdrom re
movable
cd0(pciide0:0:0): using PIO mode 4, DMA mode 2
pciide0: channel 1 ignored (disabled)
ahci0 at pci0 dev 31 function 2 "Intel 82801GBM AHCI SATA" rev 0x01: irq 10, AHC
I 1.1
scsibus1 at ahci0: 32 targets
sd0 at scsibus1 targ 0 lun 0: <ATA, TOSHIBA MK6034GS, AH10> SCSI2 0/direct fixed
sd0: 57241MB, 7297 cyl, 255 head, 63 sec, 512 bytes/sec, 117231408 sec total
usb1 at uhci0: USB revision 1.0
uhub1 at usb1: Intel UHCI root hub, rev 1.00/1.00, addr 1
usb2 at uhci1: USB revision 1.0
uhub2 at usb2: Intel UHCI root hub, rev 1.00/1.00, addr 1
usb3 at uhci2: USB revision 1.0
uhub3 at usb3: Intel UHCI root hub, rev 1.00/1.00, addr 1
usb4 at uhci3: USB revision 1.0
uhub4 at usb4: Intel UHCI root hub, rev 1.00/1.00, addr 1
isa0 at ichpcib0
isadma0 at isa0
pckbc0 at isa0 port 0x60/5
pckbd0 at pckbc0 (kbd slot)
pckbc0: using irq 1 for kbd slot
wskbd0 at pckbd0: console keyboard, using wsdisplay0
pmsi0 at pckbc0 (aux slot)
pckbc0: using irq 12 for aux slot
wsmouse0 at pmsi0 mux 0
pcppi0 at isa0 port 0x61
midi0 at pcppi0: <PC speaker>
spkr0 at pcppi0
npx0 at isa0 port 0xf0/16: reported by CPUID; using exception 16
biomask effd netmask effd ttymask ffff
pctr: 686-class user-level performance counters enabled
mtrr: Pentium Pro MTRR support
dkcsum: sd0 matches BIOS drive 0x80
root on sd0a swap on sd0b dump on sd0b
$

And here is my mixerctl:
$ mixerctl -av
outputs.dac02.source=hdaudio  [ hdaudio adc04 ]
outputs.lineout.source=dac03  [ dac03 mix0e ]
outputs.lineout.mute=off  [ off on ]
outputs.lineout=124,124
outputs.lineout=85,85
outputs.lineout.dir=output  [ input output ]
outputs.lineout.boost=off  [ off on ]
outputs.hp.source=dac03  [ dac03 mix0e ]
outputs.hp.mute=off  [ off on ]
outputs.hp=124,124
outputs.hp.boost=off  [ off on ]
outputs.mono.mute=off  [ off on ]
outputs.mono=124
outputs.mic=255,255
outputs.linein.source=dac03  [ dac03 mix0e ]
outputs.linein.mute=off  [ off on ]
outputs.linein=124,124
outputs.linein=85,85
outputs.linein.dir=input  [ input output ]
inputs.sel0b.source=dac03  [ dac03 mix0c linein mix0e lineout mic2 ]
inputs.beep.source=beep10  [ beep10 black16 ]
outputs.beep.mute=off  [ off on ]
outputs.beep=119
outputs.sel11.mute=off  [ off on ]
outputs.sel11=120,120
outputs.sel12.mute=off  [ off on ]
outputs.sel12=120,120
outputs.sel13.mute=off  [ off on ]
outputs.sel13=120,120
outputs.pow14.source=beep  [ beep mix0e sel13 speaker ]
inputs.sel15.source=mix0c  [ mix0c linein mix0e mix0f cd lineout mic2 aux ]
outputs.sel15.mute=off  [ off on ]
outputs.sel15=119,119
outputs.mic2.source=dac03  [ dac03 mix0e ]
outputs.mic2.mute=off  [ off on ]
outputs.mic2=124,124
outputs.mic2=85,85
outputs.mic2.dir=input  [ input output ]
outputs.sel1a.mute=off  [ off on ]
outputs.sel1a=120,120
outputs.sel1b.mute=off  [ off on ]
outputs.sel1b=120,120
outputs.sel1c.mute=off  [ off on ]
outputs.sel1c=120,120
outputs.speaker.mute=off  [ off on ]
outputs.speaker=240,240
outputs.sel1e.mute=off  [ off on ]
outputs.sel1f.mute=off  [ off on ]
inputs.usingdac=03  [ 03 02 ]
$
As you can see I dont have "outputs.master" setting so maybe the
problem is there though I don't know because I'm new to *BSDs.

I tried to make all settings as high as it could be (with mixerctl)
but anyway there is no sound/noice when:
$ cat ~/BIGFILE > /dev/audio
$
though there is no error messages too.

There is no /etc/mixerctl.conf on my system:
$ ls /etc/mixerctl.conf
ls: /etc/mixerctl.conf: No such file or directory
$

So... any suggestions to make my AC'97 sound work?

2007/8/29, Peter N. M. Hansteen <peter@bsdly.net>:
quoted text
> "Vim Visual" <vim.unix@googlemail.com> writes:
>
> > That made it!
>
> Good to hear that it worked.
>
> > I must be blind. I didn't think of that possibility at all... Now I'll
> > have to compile my own kernel, I guess... brrrr...
>
> Actually, you can just config -e after the first boot, enable acpi,
> quit and copy the modified kernel to /bsd.mp, just like it says in the
> FAQ (actually making /bsd a link to /bsd.mp works too and ensures you
> will always be booting the mp kernel)
>
> > Now let's wait for Damien Bergamini The Great to have some time to
> > finish the support of the wireless 4965AGN chip in wpi(4)
>
> The only remaining nit I have with my thinkpad is the still-flaky wpi
> firmware which is needed for the 3945ABG to work.  It keeps nodding
> off at random intervals, longer intervals now than earlier, but still.
>
> > I'll have to investigate a bit more about the sound issue... no sound
> > until now...
>
> It looks like your sound chip is a bit newer than the one in mine (not
> surprising), I have
>
> azalia0 at pci0 dev 27 function 0 "Intel 82801GB HD Audio" rev 0x02: apic 2 int 17 (irq 11)
> azalia0: host: High Definition Audio rev. 1.0
> azalia0: codec: Analog Devices AD1981HD (rev. 2.0), HDA version 1.0
> azalia0: codec: Conexant/0x2bfa (rev. 0.0), HDA version 0.9
> azalia0: codec[1]: No support for modem function groups
> azalia0: codec[1]: No audio function groups
> audio0 at azalia0
>
> getting sound out of that required
>
> # mixerctl outputs.lineout=255,255
>
> or an equivalent line in /etc/mixerctl.conf, plus presssing and
> holding the 'volume up' button for a while.
>
> - P
> --
> Peter N. M. Hansteen, member of the first RFC 1149 implementation team
> http://bsdly.blogspot.com/ http://www.datadok.no/ http://www.nuug.no/
> "Remember to set the evil bit on all malicious network traffic"
> delilah spamd[29949]: 85.152.224.147: disconnected after 42673 seconds.