I'm having about the same problem in my Acer Aspire 5742Z. Hotkeys bring up the brightness window, and they modify the values of the files in the /sys/devices/virtual/backlight/acpi_video0 interface, but the actual brightness isn't really changed.
A minor difference with the original reporter is that any changes I make in the acpi_video0/brightness file don't work after reboot either. Booting with "acpi=off" makes my brightness keys actually work again (am I losing anything more significant than brightness with "acpi=off"?). On the other hand, "acpi_backlight=vendor" or "acpi.brightness_switch_enabled=0" don't have any effect, brightness doesn't work with them. I upgraded by BIOS to the latest available firmware, and I'm attaching the DSDT.dsl output as suggested in https://wiki.ubuntu.com/BIOSandUbuntu#Buggy%20DSDT ** Attachment added: "DSDT.dsl" https://bugs.launchpad.net/ubuntu/+bug/741223/+attachment/2383313/+files/DSDT.dsl -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/741223 Title: Natty: Unable to adjust brightness for Acer Aspire 5731, requires reboot to reflect change To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+bug/741223/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
