Re: [PATCH] drm/radeon: add new AMD ACPI header and update relevant code

[Luca Tettamanti <kronos.it@gmail.com>]

On Thu, Jul 26, 2012 at 03:42:26PM -0400, Alex Deucher wrote:
> On Thu, Jul 26, 2012 at 3:33 PM, Luca Tettamanti <kronos.it@gmail.com> wrote:
> > On Thu, Jul 26, 2012 at 11:35:25AM -0400, Alex Deucher wrote:
> >> On Thu, Jul 26, 2012 at 8:58 AM, Luca Tettamanti <kronos.it@gmail.com> wrote:
> >> > The other missing bit is how to actually change the brightness... Alex,
> >> > do you know what registers to poke?
> >>
> >> You need to check if the GPU controls the backlight or the system
> >> does.  I think the attached patches should point you in the right
> >> direction.
> >
> > Yep :)
> >
> > 0050:  ATOM_FIRMWARE_CAPABILITY_ACCESS usFirmwareCapability :
> >   0050:  (union) ATOM_FIRMWARE_CAPABILITY sbfAccess          :
> >     USHORT GPUControlsBL:1                              = 0x0001     (1)
> >
> > The panel is using the INTERNAL_UNIPHY encoder, and I see the
> > UNIPHYTransmitterControl command table.
> >
> > Interaction with video.ko is still a bit messy...
> >
> > Do you already have code for handling the notifications? I'll work on it
> > in the weekend otherwise ;)
> 
> I don't have patches for that.  Please feel free to work on it :)

I just found the first problem (probably a BIOS bug):
ATIF_FUNCTION_GET_SYSTEM_PARAMETERS is implemented in the DSDT, but the
corresponding bit ATIF_GET_SYSTEM_PARAMETERS_SUPPORTED is not set :(
I intended to use the method to set up the notification handler but now
my BIOS says that it's not there even if it is...
Can I assume some default values (e.g. notifications are enabled and will
use 0x81 unless ATIF_FUNCTION_GET_SYSTEM_PARAMETERS says something
different)?

thanks,
Luca