After the latest Xorg upgrade I started experiencing multiple problems concerning the suspend/resume cycle on my laptop. Today I took sometimes off to debug the situation. It seems that the culprit is the activation of the KMS on the XOrg package that landed in unstable in December. The change log witness this change:
xserver-xorg-video-intel (2:2.9.1-2) unstable; urgency=low
* Upload to unstable.
-- Julien Cristau <jcristau@debian.org> Thu, 07 Jan 2010 20:53:45 +0000
xserver-xorg-video-intel (2:2.9.1-1+exp1) experimental; urgency=low
[ Julien Cristau ]
* Enable kernel mode setting by default on linux (closes: #555906).
[ Brice Goglin ]
* Build against xserver 1.7.
-- Brice Goglin <bgoglin@debian.org> Wed, 02 Dec 2009 15:50:17 +0100
now while this is the right thing to do according to bug #555906 , I’m pretty sure this is the cause of my problems.
The ubuntu wiki has a detailed page about KMS, how to enable it and bugs reports. For a start I disabled the KMS adding the following lines to /etc/initramfs-tools/modules :
intel_agp
drm
i915 modeset=0
And regenerate your initramfs (mind that this regenerate the initramfs for the running kernel):
update-initramfs -k `uname -r` -u
With this change I’ve got to the point where I can suspend/resume and switch back to a console if there is a problem. I’ve tested this with the kernel 2.6.31 and 2.6.32-trunk . The funny thing is that it seems the problem is quite random. The first suspend (hw or soft suspend gives the same result) is often ok. the second one usually fails. The logs of the X server do not tell me anything useful as much as the dmesg . To put a cherry on the cake, the iwlgn driver (intel again !) of my wireless card sometimes does not wake up properly (no useful messages again) forcing me to rmmod it and modprobe it back to spin it back to like. Grrr.
So I haven’t actually solved the problem, but maybe somebody will get a bit further reading this enty.
At least now I’ve the ability to switch back to a console and restart gdm.
In other news, since I screwed my grub on friday and I had to fix it somehow with an external boot loader, this is the easiest way I’ve found to create a rescue system on a usb key : http://wiki.debian.org/DebianLive/Howto/USB (using the rescue live CD image).
Easiest as in : “dd the image on the key and be happy”
Update
This is the page of the intel driver : http://www.x.org/wiki/IntelGraphicsDriver Gentoo page (always a good resource) : http://en.gentoo-wiki.com/wiki/Intel_GMA