I'm on 13.04 beta 2 the problem persist, even adding acpi_backlight=vendor to the boot parameters. I'm on kernel 3.8.0-18 and a12 bios firmware version for my studio 1558
I'm on 13.04 beta 2 the problem persist, even adding acpi_backlight= vendor to the boot parameters. I'm on kernel 3.8.0-18 and a12 bios firmware version for my studio 1558