I can confirm this on Vivid with the proprietary nvidia driver (version 346) installed. With switchable graphics disabled, I have an acpi_video0 backlight that does nothing. That is, the contents of /sys/class/backlight/acpi_video0/backlight changes, but the screen's brightness does not. If I enable switchable graphics, then I have only a /sys/class/backlight/intel_backlight, and it works.
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1411514 Title: [Dell Precision M4800] Brightness can't be controlled on 14.04.1 To manage notifications about this bug go to: https://bugs.launchpad.net/hwe-next/+bug/1411514/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
