Do you own a thinkpad X40, or a similar device - specifically one which needed the S3 hacks to get the backlight back on after resume? If you aren't sure, lshal | grep quirk should tell you (if you have hal). You're looking for something like power_management.quirk.s3_bios = true (and s3_mode).

Kernel 2.6.26 added a lot of quirk handling into the drivers, meaning an end to user-space hacks. pm-suspend, from the pm-utils package, assumes that all of these quirks have been resolved, but it seems that the S3 ones for my hardware have not. This means broken suspend/resume out-of-the-box. This is fixed in a version of pm-utils to be released in a week or thereabouts, after the freeze begins.

The X40 at one point seemed to be the Debian hacker's laptop of choice. I bought mine after glowing recommendations from Steve McIntyre, Stephen Gran, Mark Hymers, Amaya Rodrigo, Daniel Stone, Matthew Garrett, Rob McQueen and several others. It's one of the best pieces of hardware I've ever had the pleasure of using, and I'm concerned that we might even be going backwards in terms of supporting this device from release-to-release.

If you do have such a device, can you please try the following:

  • install the 2.6.26 kernel
  • boot into single user mode

  • modprobe i915

  • echo mem > /sys/power/state

  • resume your laptop

Please try this and report to me whether the backlight came back on - either in the discussion page for this post, or via email (jon.backlight@alcopop.org). The kernel bug to try and get this fixed is http://bugzilla.kernel.org/show_bug.cgi?id=10985, but it might not be possible to backport a fix for this to the Lenny kernel. The bug against pm-utils regarding assuming 2.6.26 is quirk-free is https://bugs.freedesktop.org/show_bug.cgi?id=16453 (Debian bug http://bugs.debian.org/488144).