I have the same bug on a HP TouchSmart tm2, with the added bonus that the backlight problems also happen at startup every now and then.
The easiest way I have found to trigger this situation is to set brightness to 0 on a terminal (as root) echo 0 > /sys/class/backlight/acpi_video0/brightness Any other brightness set in this way is applied correctly. However, after setting 0, the backlight never comes back on. A workaround I use is to change screen orientation. For some reason, the command xrandr -o right (followed by xrandr -o normal to get it back to normal) changes so many things in the display settings that the backlight comes back on. I have now assigned hotkeys to these commands, so that I can log in blindly, then press the hotkeys, and have a working backlight. I should also note that this problem does not occur after switching to ATI graphics with the vga_switcheroo kernel module. -- [gm45] Backlight sometimes stays off after resume on Lenovo X200 https://bugs.launchpad.net/bugs/580225 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
