Forwarding this bug from Ubuntu reporter Laurent:
Black screen on boot after the ISOLINUX menu on an i855GM card.
On Karmic Koala 9.10 Alpha 3 live Cd, after ISOLINUX menu the screen becomes definitively black.
Toshiba laptop with Intel 855GM graphic card
For me, no mouse pointer shows, just the whole screen black ..
- Disable usplash doesn't correct the problem
- Lower/other resolution doesn't correct the problem
My problem seems linked to KMS as i915.modeset=0 permit to have a console but X don't start because of no valid mode detect for LVDS
Register dump when it work in Jaunty with intel 2:2.7.1-0ubuntu1~xup~1 is included. I'm still trying too find a way to do the same with Kamic koala when it's not good.
DistroRelease: Ubuntu 9.04
MediaBuild: Ubuntu 9.10 "Karmic Koala" - Alpha i386 (20090722.2)
Package: xorg 1:7.4~5ubuntu18
ProcEnviron: PATH=(custom, user)
ProcVersion: Linux version 2.6.30-020630-generic (root@zinc) (gcc version 4.2.3 (Ubuntu 4.2.3-2ubuntu7)) #020630 SMP Wed Jun 10 09:45:40 UTC 2009
Uname: Linux 2.6.30-020630-generic i686
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(this was an old conf not the one used with the livecd boot, so probably irrelevant to the problem.)
Looks like LVDS mode detect issue. So if it's possible to get kernel log with ubuntu default KMS enabled kernel, please append "drm.debug=15" to kernel boot option and attach kernel log.
Or with i915.modeset=0, enable "ModeDebug" option in xorg.conf, then attach X log.
Do you mean in jaunty UMS driver this machine is fine? maybe try recent 2.8.0 driver in UMS is also a good test.
Created attachment 28789 [details]
Karmic Xorg.0.log with "ModeDebug" enable and "i915.modeset=0"
It isn't possible to get a console with normal startup : screen become completly black (even backlight is shut off). And as it's a liveCD, no remote access is possible ==> same behavior with "drm.debug=15" at kernel boot.
Attached file Xorg.0.Log.ModeDebug.txt is with i915.modeset=0 and ModeDebug (I have generate a xorg.conf with -configure option and the added "ModeDebug" Option)
In Jaunty it work fine with kernel 2.6.30-020630-generic and driver 2.7.1.(from xup repo)
But with kernel 2.6.31-5-generic, I have also a black screen until I had i915.modeset=0 and xorg start.
I had also try 2.8.0 driver, some week ago, with kernel 2.6.30-020630-generic but as xorg didn't want to start, I had removed it and fall back to 2.7.1 (without keeping log).
If you need I can make a second try and keeping log you need ?
thanks, your log showed you're using 2.8.0 driver already. The problem is LVDS can't find any mode, as your LVDS has no EDID, and our VBT parsing might be broken.
So please attach your vbios dump, do like below:
echo 1 > /sys/devices/pci0000\:00/0000\:00\:02.0/rom
cat /sys/devices/pci0000\:00/0000\:00\:02.0/rom > /tmp/vbios
It'll be good if you can try current xf86-video-intel git tree, revert af45482a52999b52bf41468c458808e30c100e35, and try to test again.
Please attach the vbios.dump according to the instruction in comment #11.
Will you please confirm the following commit is included?
Author: Zhao Yakui <email@example.com>
Date: Fri Jul 24 10:44:20 2009 +0800
Calculate the DVO relative offset in LVDS data entry to get the DVO timing
If not, please apply it and see whether the issue still exists.
Please also attach the vbios.dump by using the instruction described in comment #11.
This box is also based on 855GM chipset and it seems that this is a duplicated of bug22787.
So this bug will be marked as the dup of bug22787.
If the problem still exists after trying the latest driver, please reopen it.
*** This bug has been marked as a duplicate of bug 22787 ***