From posted above url... "dysfunctional ACPI _BCM backlight brightness control method in the Dell Studio 1558 firmware (and likely the other 155x models). The fix involves overriding the use of the _BCM method with the Intel GPU i915 driver's opregion backlight control method. The fix will therefore affect all i915-based systems that support the opregion method not just Dell Studio systems. This does fix the brightness keys on the Dell Studio 1558 and might also fix other i915 systems with backlight brightness control problems." Reproducible: Always Steps to Reproduce: 1.Adjust laptop screen brightness with f4 f5 keys. 2. 3. Actual Results: Screen Brightness does not work Expected Results: Screen Brightness adjusts
Created attachment 279427 [details] emerge --info
Created attachment 279429 [details] .config of kernel
I also have a studio 1558, and I have no backlight control. Googling has lead me to believe that this functionality is best provided so far by the patched Ubuntu kernel here: https://launchpad.net/~kamalmostafa/+archive/linux-kamal-mjgbacklight I don't see a link for the individual patches on that site however. At one point I had this patch working, but either it doesn't apply to new kernels or I am doing something differently than before and don't realize it: http://lists.freedesktop.org/archives/dri-devel/2011-January/007167.html
Created attachment 279487 [details] .config
Ups, I see you are using hardened-sources instead :S, would be nice if you could check with hardened-sources-2.6.39-r5
I checked with linux-2.6.39-hardened-r6 and it did not fix the problem.
In the next couple of days, Linux-3.1-rc3 should be released, which will contain a patch that probably fixes the issue. If it works, I could try and backport the patch for Linux-3.0, and add it to genpatches for 3.0 kernels. Thanks.
