[Intel-gfx] [PATCH v6 02/12] drm/i915/mtl: Synchronize i915/BIOS on C6 enabling

[Dixit, Ashutosh]

On Wed, 15 Mar 2023 18:00:51 -0700, Umesh Nerlige Ramappa wrote:
>
> From: Vinay Belgaumkar <vinay.belgaumkar at intel.com>

Hi Vinay,

> If BIOS enables/disables C6, i915 should do the same.

So MTL bios has a control for enabling/disabling C6? Both RC6 and MC6
individually or collectively?

What happens if bios has disabled RC6 and i915 enables it: just that it
will bust OA?

The patch itself LGTM if the above is true, I can R-b it after I hear about
the above.

Thanks.
--
Ashutosh

> Also, retain this value across driver reloads. This is needed only for
> MTL as of now due to an existing bug in OA which needs C6 disabled for it
> to function. BIOS behavior is also different across platforms in terms of
> how C6 is enabled.
>
> Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar at intel.com>