Re: no brightness with acpi video since 3.3 [was Re: Issues with the sony-platform module]

[Zhang Rui <rui.zhang@intel.com>]

On 五, 2012-06-15 at 05:39 +0900, Mattia Dongili wrote:
> On Thu, Jun 14, 2012 at 07:33:05PM +0200, Karol Babioch wrote:
> > Hi,
> > 
> > I'm a user of the Sony VAIO VPCS12C5E and as such have always struggled
> > with the Linux support of my laptop basically forever. Until now I've
> > used the patch provided here [1], which worked quite well for some time.
> > However since kernel version 3.3 I couldn't change the brightness of my
> > screen anymore.
> 
> This is not an issue with the platform driver but with the acpi video
> driver.
> 
so ACPI video driver is used before 3.3 and it works?
please try this patch
https://bugzilla.kernel.org/attachment.cgi?id=73576
and boot without acpi_backlight=vendor and see if it helps.

thanks,
rui

> You can boot with acpi_backlight=vendor and get brightness control back
> but the issue with acpi_video remains.
> 
> ...
> > So, I've uploaded a dmesg log when loading the module with the debug
> > option enabled and trying to change the brightness with the fn keys here
> > [2]. Maybe this is already enough to nail the issue down. Otherwise just
> > let me know what you would like to have.
> 
> please provide your laptop's DSDT table as well.
> 
> > [1] https://code.google.com/p/vaio-f11-linux/wiki/KernelSupport
> > [2] http://pastebin.com/GRrtp024
> 
> Thanks