No brightness control - Sony VAIO VPCCW2 and driver 260.19.29

[rohandhruva]

Hi,

I have a Sony Vaio VPCCW2 laptop with NVidia GT310M card. Brightness control using hotkeys is not working for me. I tried using the nvidiabl driver (http://www.nvnews.net/vbulletin/showthread.php?t=143025) but it just leads to a black screen as posted here - http://www.nvnews.net/vbulletin/show...5&postcount=86

While going through the X.org log, I noticed this message:

[    20.086] (WW) NVIDIA(0): ACPI: Error: Unable to find the brightness file path under
[    20.086] (WW) NVIDIA(0):     /proc/acpi/video. The NVIDIA X driver will not be able to
[    20.086] (WW) NVIDIA(0):     respond to ACPI brightness change hotkey events.
[    20.088] (II) NVIDIA(0): Setting mode "nvidia-auto-select"

Is there any way to get my laptop video brightness control supported 'upstream'? How do I get the required 'brightness' file in /proc/acpi/video?

Thanks!

PS: Brightness control works when using nouveau, but it has a very high value for max_brightness (in thousands), and hence most brightness applets fail, and I am forced to use acpi scripts.