hdaudio driver too quiet on 82801H (Conexant) device

[halfbeing]

"Eleven. That's one more innit?"

The maximum output volume on the 82801H device on my laptop is much lower than that produced by the ALSA driver. Through headphones, the ALSA goes way beyond deafening before it starts clipping, whereas the OSS4 driver falls way short of deafening, enough to make it hard to use for VOIP.

One thing I am really not clear about is whether there are any audio settings that survive reboot cycles. I didn't notice this problem when I first started using OSS4, but during one session I noticed three times a clicking sound followed by a drop in volume, until there was just silence. It was not long after that that I first noticed the weak volume level. The reason I decided to switch to OSS4 in the first place was because all of a sudden the mic input level in ALSA jumped and made the mic unusable because of clipping. In other words, on the same kernel, the level changed, but I couldn't change it back again because none of the sliders in kmix that are supposed to control the input level work. If someone could answer this general question about whether there are persistent settings I would be very grateful because if I can get either ALSA or OSS4 to work reasonably well I will be happy. And just in case you are wondering, OSS4 is the front runner at the moment.

But back to me original question, whether it is actually connected to persistent settings or not, how can I get a decent volume level on my current hardware?

[cesium]

Yes, persistent settings exist in OSS4. The "savemixer" utility is automatically run when OSS4 starts to restore volume settings from /usr/lib/oss/mixer.save, and when OSS4 is unloaded to save mixer setting to that file. You can run it manually ("sudo savemixer" - sudo is required since only root has permissions to write to that file) to save the mixer settings.

Secondly, please post output of "ossmix" and "ossinfo -v3", so we can tell what codec is used and what the mixer settings are.

[halfbeing]

Thanks for the quick reply

robert@ermintrude:~$ ossmix
Selected mixer 0/High Definition Audio CX20548
Known controls are:
jack.int-speaker.mode <pcm1> (currently pcm1)
jack.int-speaker.int-speaker [<leftvol>:<rightvol>] (currently 64.4:64.4 dB)
jack.green.mode <pcm1> (currently pcm1)
jack.green.headphone [<leftvol>:<rightvol>] (currently 61.4:61.4 dB)
jack.pink.mode <pcm1> (currently pcm1)
jack.pink.mic1 [<leftvol>:<rightvol>] (currently 47.9:47.9 dB)
jack.black.mode <pcm2> (currently pcm2)
record.rec1 [<leftvol>:<rightvol>] (currently 7.4:7.4 dB)
record.rec1.rec1 <mix> (currently mic2)
misc.beep <monovol> (currently 17.9 dB)
misc.pcm1 [<leftvol>:<rightvol>] (currently 53.9:53.9 dB)
misc.mic2 [<leftvol>:<rightvol>] (currently 52.4:52.4 dB)
misc.mic1 [<leftvol>:<rightvol>] (currently 59.9:59.9 dB)
misc.headphone [<leftvol>:<rightvol>] (currently 50.9:50.9 dB)
misc.int-mic [<leftvol>:<rightvol>] (currently 47.9:47.9 dB)
misc.mix <pcm1> (currently pcm1)
vmix0-enable ON|OFF (currently ON)
vmix0-rate <decimal> (currently 48000) (Read-only)
vmix0-channels <Stereo> (currently Multich)
vmix0-src <Fast> (currently High)
vmix0-outvol <monovol> (currently 25.0 dB)
vmix0-invol <monovol> (currently 25.0 dB)
vmix0.pcm5 [<leftvol>:<rightvol>] (currently 25.0:25.0 dB)
vmix0.pcm6 [<leftvol>:<rightvol>] (currently 25.0:25.0 dB) ("plasma")
vmix0.pcm7 [<leftvol>:<rightvol>] (currently 25.0:25.0 dB)
vmix0.pcm8 [<leftvol>:<rightvol>] (currently 25.0:25.0 dB)
robert@ermintrude:~$
robert@ermintrude:~$
robert@ermintrude:~$
robert@ermintrude:~$ ossinfo -v3
Version info: OSS 4.2 (b 2000/200909142308) (0x00040100) GPL
Platform: Linux/x86_64 2.6.31-rt9ish #11 SMP PREEMPT RT Tue Sep 15 01:03:30 CEST 2009 (ermintrude)

Number of audio devices: 5
Number of audio engines: 9
Number of MIDI devices: 0
Number of mixer devices: 1


Device objects
0: osscore0 OSS core services
1: oss_hdaudio0 Intel HD Audio interrupts=25680233 (25680233)
HD Audio controller Intel HD Audio
Vendor ID 0x8086284b
Subvendor ID 0x17aa20ac
Codec 0: CX20548 (0x14f15045/0x17aa20db)
2: oss_usb0 USB audio core services

MIDI devices (/dev/midi*)

Mixer devices
0: High Definition Audio CX20548 (Mixer 0 of device object 1)
Device file /dev/oss/oss_hdaudio0/mix0, Legacy device /dev/mixer0
Priority: 10
Caps:
Device handle: PCI20ac17aa-0000:00:1b.0-mx01
Device priority: 10


Audio devices
HD Audio play pcm1 /dev/oss/oss_hdaudio0/pcm0 (device index 0)
Legacy device /dev/dsp0
Caps: DUPLEX TRIGGER MMAP
Modes: IN/OUT
Out engine 1: 0/HD Audio play pcm1
Busy (OUT) label 'VMIX'
Engine 2: 5/HD Audio play pcm1 (vmix)
Available for use
Engine 3: 6/HD Audio play pcm1 (vmix)
Busy (OUT) by PID 4710 / plasma label 'plasma'
Engine 4: 7/HD Audio play pcm1 (vmix)
Available for use
Engine 5: 8/HD Audio play pcm1 (vmix)
Available for use
Input formats (0x00001010):
AFMT_S16_LE - 16 bit signed little endian
AFMT_S32_LE - 32 bit signed little endian
Output formats (0x00001010):
AFMT_S16_LE - 16 bit signed little endian
AFMT_S32_LE - 32 bit signed little endian
Device handle: PCI20ac17aa-0000:00:1b.0-au01
Related mixer dev: 0
Sample rate source: 0
Preferred channel configuration: Not indicated
Supported number of channels (min - max): 2 - 8
Native sample rates (min - max): 48000 - 192000 (48000,96000,192000)
HW Type: Not indicated.
Minimum latency: Not indicated

HD Audio play pcm2 /dev/oss/oss_hdaudio0/pcm1 (device index 1)
Legacy device /dev/dsp1
Caps: TRIGGER MMAP
Modes: OUTPUT
Out engine 1: 1/HD Audio play pcm2
Available for use
Input formats (0x00000010):
AFMT_S16_LE - 16 bit signed little endian
Output formats (0x00000010):
AFMT_S16_LE - 16 bit signed little endian
Device handle: PCI20ac17aa-0000:00:1b.0-au02
Related mixer dev: 0
Sample rate source: 0
Preferred channel configuration: Not indicated
Supported number of channels (min - max): 2 - 2
Native sample rates (min - max): 16000 - 48000 (16000,48000)
HW Type: Not indicated.
Minimum latency: Not indicated

HD Audio play spdifout2 /dev/oss/oss_hdaudio0/spdout0 (device index 2)
Legacy device /dev/dsp2
Caps: TRIGGER MMAP
Modes: OUTPUT
Out engine 1: 2/HD Audio play spdifout2
Available for use
Input formats (0x00001410):
AFMT_S16_LE - 16 bit signed little endian
AFMT_AC3 - AC3 (Dolby Digital) encoded audio
AFMT_S32_LE - 32 bit signed little endian
Output formats (0x00001410):
AFMT_S16_LE - 16 bit signed little endian
AFMT_AC3 - AC3 (Dolby Digital) encoded audio
AFMT_S32_LE - 32 bit signed little endian
Device handle: PCI20ac17aa-0000:00:1b.0-au03
Related mixer dev: 0
Sample rate source: 0
Preferred channel configuration: Not indicated
Supported number of channels (min - max): 2 - 2
Native sample rates (min - max): 48000 - 48000 (48000)
HW Type: Not indicated.
Minimum latency: Not indicated

HD Audio rec rec1 /dev/oss/oss_hdaudio0/pcmin0 (device index 3)
Legacy device /dev/dsp3
Caps: DUPLEX TRIGGER MMAP
Modes: IN/OUT
In engine 1: 3/HD Audio rec rec1
Busy (IN) label 'VMIX_IN'
Engine 2: 5/HD Audio play pcm1 (vmix)
Available for use
Engine 3: 6/HD Audio play pcm1 (vmix)
Busy (OUT) by PID 4710 / plasma label 'plasma'
Engine 4: 7/HD Audio play pcm1 (vmix)
Available for use
Engine 5: 8/HD Audio play pcm1 (vmix)
Available for use
Input formats (0x00001010):
AFMT_S16_LE - 16 bit signed little endian
AFMT_S32_LE - 32 bit signed little endian
Output formats (0x00001010):
AFMT_S16_LE - 16 bit signed little endian
AFMT_S32_LE - 32 bit signed little endian
Device handle: PCI20ac17aa-0000:00:1b.0-au04
Related mixer dev: 0
Sample rate source: 0
Preferred channel configuration: Not indicated
Supported number of channels (min - max): 2 - 2
Native sample rates (min - max): 48000 - 96000 (48000,96000)
HW Type: Not indicated.
Minimum latency: Not indicated

HD Audio rec pcm2 /dev/oss/oss_hdaudio0/pcmin1 (device index 4)
Legacy device /dev/dsp4
Caps: TRIGGER MMAP
Modes: INPUT
In engine 1: 4/HD Audio rec pcm2
Available for use
Input formats (0x00000010):
AFMT_S16_LE - 16 bit signed little endian
Output formats (0x00000010):
AFMT_S16_LE - 16 bit signed little endian
Device handle: PCI20ac17aa-0000:00:1b.0-au05
Related mixer dev: 0
Sample rate source: 0
Preferred channel configuration: Not indicated
Supported number of channels (min - max): 2 - 2
Native sample rates (min - max): 16000 - 48000 (16000,48000)
HW Type: Not indicated.
Minimum latency: Not indicated


Nodes
/dev/dsp -> /dev/oss/oss_hdaudio0/pcm0
/dev/dsp_in -> /dev/oss/oss_hdaudio0/pcm0
/dev/dsp_out -> /dev/oss/oss_hdaudio0/pcm0
/dev/dsp_ac3 -> /dev/oss/oss_hdaudio0/spdout0
/dev/dsp_mmap -> /dev/oss/oss_hdaudio0/pcm0
/dev/dsp_multich -> /dev/oss/oss_hdaudio0/pcm0
robert@ermintrude:~$

[halfbeing]

When I was asking about persistent settings, I meant were there any settings stored on the machine that would be used by the firmware of the audio device quasi-independently of the operating system. I'm really struggling to understand how – certainly in ALSA, and perhaps in OSS4 as well – a parameter that doesn't see to be controllable through the driver's interface could change.

[halfbeing]

To add to all of the above, I now seem to be experiencing random changes in volume, sometimes matched by a change in the volume level as indicated in ossxmix. These happen several times a minute and cumulatively can take the volume from loud to almost silent and back again. Killing ossxmix doesn't cure it.

I know that you are not a huge operation, and I really admire the work you have been putting in, so I hope you will forgive me asking a very direct question. Do you think there is a realistic prospect of these problems being resolved in the near future? I've been using Linux for a long time, but the audio problems I have been having are insufferable and I need to decide whether I should go back to using Windows and/or save up for a Mac.