After a fresh install of Ubuntu, I discovered the function keys for screen brightness control (Fn+F4 and Fn+F5 in that case) are not functioning. Digging around here, I managed to get them to work by following a solution suggested on several posts, but alas — after applying it, a strange problem occurred:
When setting the brightness level to any value other than minimum or maximum, the screen starts flickering back and forth from the selected level to full brightness, apparently due to Dell's power saver attempting to dim the screen to auto-adjust brightness levels.
I looked up for a solution here on the site, and possibly everywhere, with no avail. Also tried:
- To manually control the brightness by configuring the ACPI level (setting values by
echo [some_value] | sudo tee /sys/class/backlight/[vendor]_backlight/[some_key], without success.
- Installing the Intel graphics driver, thinking it's missing. Realized it's installed out of the box by installing Mesa Utils.
How to resolve this?
- Model: Dell Studio XPS 13
- OS: Windows 7 64bit / Ubuntu 12.04 32bit (dual boot)
- Graphics Driver: Intel HD 3000 (Sandybridge Mobile x86/MMX/SSE2)
lshw -C displayoutput:
*-display description: VGA compatible controller product: 2nd Generation Core Processor Family Integrated Graphics Controller vendor: Intel Corporation physical id: 2 bus info: pci@0000:00:02.0 version: 09 width: 64 bits clock: 33MHz capabilities: msi pm vga_controller bus_master cap_list rom configuration: driver=i915 latency=0 resources: irq:47 memory:f0000000-f03fffff memory:e0000000-efffffff ioport:2000(size=64)