Upon upgrading from
13.10, I am no longer able to change the brightness via KDE system settings or the battery monitor widget. Upon editing my
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"
I am able to modify brightness via keyboard controls but not via system settings or the battery monitor widget.
Brightness appears to be at 100% on startup.
xbacklight does not change when given commands such as
xbacklight -set 50.
Additionally, I periodically get the error notification:
Wireless Interface wlan0 failed to activate - Authorization Supplicant timed out.
I am using a Lenovo Thinkpad T430s with Nvidia Optimus graphics and an Intel wireless card. All settings worked fine before the upgrade.