ACPI DSDT has actually two paths for changing backlight. One is simple to understand and is using SMI Command Port B2, but only works when booting with BIOS. The other is quite complicated (for me acpi noob) and is using a ressource called "smbus-ddcblc". I don't know if the backlight acpi is failing because it doesn't follow the right code path (in which case acpi think it's bios where it isn't) or because memory is not mapped as acpi thinks it should be, or... ?
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/818826 Title: backlight brightness control won't work in 2011 iMac 27" To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-power-manager/+bug/818826/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
