Kernel Bug Tracker – Bug 15286
Cannot change brightness with Intel Arrandale on Sony VPCS111FM laptop
Last modified: 2010-04-03 22:59:52 UTC
Created attachment 25008 [details]
tar'd bzip of various items of output that will be requested
Same results in kernels:
* 126.96.36.199 vanilla
* gentoo-sources-2.6.32-r4 (above + gentoo patches)
All tests in attached output from vanilla kernel.
I have searched for similar bug reports, and didn't find anything that helped. I have attached a tar'd bzip of all debug information I've collected that seemed to be asked in other similar reports.
--> Contents of tar:
I have a fairly new Sony VPCS111FM. It's pretty much an Intel-everything laptop.
--> see lspci-tv.output
I cannot change the laptop brightness. From what I can tell, it looks like Kernel Mode Setting is required (?) on this machine/chipset to get X started, as I get a blank/black screen w/o KMS (using xf86-video-intel-2.9.1).
I have attempted to use the kernel parameter "acpi_brightness" set to either 'vendor' or 'video', and have attached various outputs that show the contents of /proc/acpi and /sys/class/backlight under both cases. 'vendor' gets me further, as the 'sony' directory and subentries appear in /sys/class/backlight, but they do not change the physical appear of the brightness of the screen. When in 'vendor' mode, neither xbacklight nor xrandr (for brightness) works.
--> see vendor-*
I have also attached a binary DSDT dump.
--> see dsdt.bin
I'm happy to try anything, as I'm completely at a loss after much debugging and trial and error.
*** This bug has been marked as a duplicate of bug 15279 ***