Comment 7 for bug 398026

Created an attachment (id=27664)
Image054.jpg

Forwarding this bug from Ubuntu reporter Chris Halse Rogers:
https://bugs.edge.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/398026

[Problem]
Recently for LVDS, the driver sometimes chooses a mode with the preferred resolution but with an inappropriate frequency (60 Hz instead of 50 Hz).

A similar bug (believed to be a dupe) with 85 Hz being selected instead of the more correct 60 Hz is here:
https://bugs.edge.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/396171

[Original Report]
The latest version of xserver-xorg-video-intel fails to drive my laptop's LVDS display correctly at the default 60Hz refresh rate. It works fine at 50Hz.

Taking a screenshot reveals a normal desktop, so this is a problem somewhere in the scanout.

Attached photo shows the 60Hz display problem - bands of the display are stretched horizontally. It looks pretty cool!

The previous version of xserver-xorg-video-intel (...git20090602) had a bug in which only the preferred mode from the EDID information would be available (https://bugs.freedesktop.org/show_bug.cgi?id=20801). In ...git20090702 this bug is fixed and also other modes are available. The problem seems to be that for LVDS output the driver sometimes chooses a mode with the preferred resolution, but with a higher frequency (85 Hz instead of 60 Hz in bug 396171 and 60 Hz instead of 50 Hz in bug 398026).

ProblemType: Bug
Architecture: amd64
Date: Sat Jul 11 08:31:32 2009
DistroRelease: Ubuntu 9.10
MachineType: LENOVO 7465CTO
Package: xserver-xorg-video-intel 2:2.7.99.901+git20090702.74227141-0ubuntu1
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.31-2-generic root=/dev/mapper/Storage-Ubuntu--Root ro quiet splash crashkernel=384M-2G:64M,2G-:128M
ProcEnviron:
 PATH=(custom, user)
 LANG=en_AU.UTF-8
 SHELL=/bin/zsh
ProcVersionSignature: Ubuntu 2.6.31-2.16-generic
RelatedPackageVersions:
 xserver-xorg 1:7.4+3ubuntu5
 libgl1-mesa-glx 7.5~rc4-1ubuntu3
 libdrm2 2.4.11-1ubuntu1
 xserver-xorg-video-intel 2:2.7.99.901+git20090702.74227141-0ubuntu1
 xserver-xorg-video-ati 1:6.12.99+git20090629.f39cafc5-0ubuntu1
SourcePackage: xserver-xorg-video-intel
Uname: Linux 2.6.31-2-generic x86_64
XorgConf: Error: [Errno 2] No such file or directory: '/etc/X11/xorg.conf'
dmi.bios.date: 04/22/2009
dmi.bios.vendor: LENOVO
dmi.bios.version: 6DET44WW (2.08 )
dmi.board.name: 7465CTO
dmi.board.vendor: LENOVO
dmi.board.version: Not Available
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvr6DET44WW(2.08):bd04/22/2009:svnLENOVO:pn7465CTO:pvrThinkPadX200s:rvnLENOVO:rn7465CTO:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 7465CTO
dmi.product.version: ThinkPad X200s
dmi.sys.vendor: LENOVO
fglrx: Not loaded
system:
 distro: Ubuntu
 architecture: x86_64kernel: 2.6.31-2-generic