I used the script by Franklin Piat to build a debian package from unreleased alsa sources. Works great once I remember the hardware volume control buttons. Doh!. A big shout-out to Franklin for what seems like a very clean solution.

Update

As of version 1.0.15-2 I am using the default alsa-modules source package, compiled via module-assistant

Suspend to disk works ok out of the box, if you type (as root)

  echo -n disk > /sys/power/state

I like the command line and all, but somehow this is a bit tedious. To get Fn-F12 working, one has to first load the thinkpad-acpi module

modprobe thinkpad-acpi

Next, one has to enable the hotkey subdriver

echo enable > /proc/acpi/ibm/hotkey

These two steps can be automated by creating /etc/acpi/start.d/40-thinkpad-acpi.sh Finally, workaround a problem with the default /etc/acpi/hibernatebtn.sh. For some reason, acpi_fakekey is not doing its magic thing, so I replaced it with a call to hibernate.sh. There are already some bug reports about this in debian. Now that we enabled thinkpad-acpi hotkeys, we have to the same hack to /etc/acpi/sleepbtn.sh

Be warned, this will may not play nicely with the kde/gnome gui suspend/resume tools

First install the firmware:

 apt-get install firmware-iwlwifi

Next, rebuild the kernel and reboot (this is not strictly necessary, but it is what I did; other people can tell you other ways), so that you have the source for the kernel you are currently running available.

Download the latest kernel module source from intellwireless.org

Unpack, make (probably twice) su, make install

Update

To avoid recompiling your kernel, you can follow the steps from Stuart Prescott

Out of the box, it will go to sleep (suspend to ram) when you hit Fn-F4, but on wakeup the backlight.
Based on a Ubuntu bug report (which I've now lost track of) that mentioned switching virtual terminals turned the backlight back on, I created /etc/apci/resume.d/99-switchvt.sh to automate that Not the most beautiful solution in the world, but it works. I have submitted a [[http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=439914][debian bug]]

• UPDATED Another workaround is to add the kernel parameter

  acpi_sleep=s3_bios

(lenny/sid) on a thinkpad x61. Initially I was running the stock 2.6.22-1-686 kernel; to get wifi going I decided to rebuild the kernel. I have installed the acpi-support package, which then requires some hacking. The various issues are tagged x61