Ubuntu 10.4 – up with only one quirk so far

This morning I let my Ubuntu 9.10 upgrade itself to 10.4. The upgrade itself ran fine with only a few interruptions where I had to confirm or deny changes to configuration files for PHP etc.

As I landed at the office and hooked up the laptop (Thinkpad T61P) however, my external monitor was flickering a lot. Tried booting into Windows and everything was fine. Google’d and found this post on Ubuntu Forums.

The post suggests making changes to menu.lst in /boot/grub. This is a somewhat short term solution, because the problem will probably reappear at the next kernel upgrade (which could be just around the corner). The fix may be on it’s way in an actual Ubuntu fix, but i chose a different approach which may also seem hack’ish – the fix could be more robust though.

Disclaimer: If you are not sure what you are doing, be very careful. Misspellings or deviations from the description below may lead to an unbootable system. This worked for me and doesn’t have to work for you. Make sure to back up any files you change.

OK? Let’s go..

First start a terminal (ALT-F2, enter “gnome-terminal”):

cd /etc/grub.d

Then:

sudo nano 10_linux

which will open an editor. Around line 96 inside the linux_entry-function is a line that looks like this:

linux    ${rel_dirname}/${basename} root=${linux_root_device_thisversion} ro ${args}

and it should be changed to:

linux    ${rel_dirname}/${basename} root=${linux_root_device_thisversion} ro radeon.modeset=0 ${args}

Having done this, you should ask grub to rebuild it’s configuration files with:

sudo update-grub

Reboot and go on without the flicker..