Linux ALSA driver
On systems where lspci shows an Intel AC'97 Audio Controller, this chip is supported by the snd-intel8x0 kernel module. This driver provides enhanced power saving capabilities.
On systems where lspci shows an ATI AC'97 Audio Controller (R40e and R51e), this chip is supported by the snd-atiixp kernel module.
If sound still doesn't work even if you have a perfectly correct setup, try turning the hardware volume up with the keyboard buttons. They are totally independent from the ALSA controls and chances are they are just muted.
On some models (T40, T43p, ... R51e ...) audio is muted if either Headphone or Line Jack are unmuted. See also ALSA Wiki FAQ . Also, if Headphone Sense or Line Jack Sense are unmuted audio is dead (R50e, R52, X40). By default the Sense settings are not shown in mixer.
By default microphone capture is disabled when using the ALSA drivers (this may or may not be true with the OSS drivers). To enable microphone capture, use amixer or gnome-alsamixer to enable capture on the microphone and Capture devices, i.e., 'amixer set 'Mic' cap; amixer sset 'Capture' cap'.
A bug was introduced in the 2.6.20 kernel (between the rc1 and rc2 releases) which causes the sound to stop working after hibernation. Rebooting does not seem to fix the problem. A quick work-around is to do a suspend-to-ram, and then wake the machine up. This issue is chronicled in this bug report on Launchpad.net: The fix changing HIBERNATE_MODE=shutdown to HIBERNATE_MODE=platform in /etc/default/acpi-support worked very well. I don't know if it possibly could introduce other bugs or if it's a true fix.
Changing HIBERNATE_MODE=shutdown to HIBERNATE_MODE=platform in /etc/default/acpi-support seems to be solving this issue for many users. Confirmed to work with: X31, T43p
FreeBSD OSS driver
snd_ich will work happily for this audio chip.
ThinkPads this chip may be found in
- R40, R40e
- R50, R50e, R50p, R51, R51e, R52
- T40, T40p, T41, T41p, T42, T42p, T43, T43p
- X31, X32
- X40, X41, X41 Tablet