Public bug reported:
Acer SK20 computer (Intel 845G graphics), Acer AL1511 LCD panel. Karmic,
kernels 2.6.31-17-generic and 2.6.31-19-generic tested. Both fail to set
the panel to its native 1024x768 resolution automatically; 640x350 mode
is chosen instead, which the panel really doesn't like (weird aspect
ratio, letterboxing, inconsistent contrast and brightness). This is a
clean install of Karmic, and the same issue occured with the live CD. It
doesn't happen with a Hardy live CD.
Two separate workarounds are required, one to set the console frame
buffer to 1024x768 and the other to make the GUI operate at that
resolution by default (with no workaround, 1024x768 *is* available in
Preferences->Display, it's just not the default).
For the frame buffer: uninstall Grub 2, install Grub, and add the
following boot options to the # kopt= and all kernel lines:
nomodeset=1 vga=791
For the GUI: start in Recovery mode, drop to a root shell, and run
X -configure
mv xorg.conf.new /etc/X11/xorg.conf
vi /etc/X11/xorg.conf
and replace all the generated "Display" subsections with
SubSection "Display"
Modes "1024x768"
EndSubSection
The attached zip file includes output from dmidecode, lspci -vnvn,
/proc/version_signature and three versions of output from dmesg and
xrandr --verbose. The -with-default-settings versions are from a boot
with default settings (no extra kernel options, no xorg.conf). The
-with-vga791 versions have the nomodeset=1 and vga=791 kernel options,
but no xorg.conf. The -with-vga791-and-xorgconf versions have both the
workarounds given above.
Thanks to Bryce Harrington for the information at
https://wiki.ubuntu.com/X/Troubleshooting/Resolution#Problem:%20%20Resolution%20with%20Intel%20graphics%20was%20correct%20in%20Intrepid%20or%20Jaunty%20%28with%20no%20xorg.conf%20configuration%29%20but%20is%20limited%20in%20Karmic
Without it, I would still be tearing hair instead of looking at a
working console frame buffer, and would not have known the right way to
submit this bug report.
Sorry if I've just submitted this report twice; got a Launchpad error on
my first try.
** Affects: linux (Ubuntu)
Importance: Undecided
Status: New
** Tags: xorg-needs-kernel-fix
--
Missing monitor quirk for Acer AL1511 results in reduced resolution
https://bugs.launchpad.net/bugs/522488
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