DCN/PP regression

[Tom St Denis]

Note:  The bug (fail to init tonga) doesn't occur on my Carrizo system 
so it definitely has something to do with the call to 
dcn_bw_update_from_pplib() on my Raven.

Tom

On 06/25/2018 09:58 AM, Tom St Denis wrote:
> With a Tonga dGPU installed in a Raven1 system I see (attached) dmesg 
> warning from init.
> 
> Also, every warm reboot results in my Tonga failing to init (also 
> attached).  If I cold reboot (hit the reset button) it works fine.
> 
> Note I get the DCN message regardless if I warm or cold reboot.
> 
> 
> commit d35c9287c92f330f07b3e87f7f2953b1c822c8e3 (HEAD, refs/bisect/bad)
> Author: Mikita Lipski <mikita.lipski at amd.com>
> Date:   Thu May 31 14:49:00 2018 -0400
> 
>      drm/amd/display: Enable PPLib calls from DC on linux
> 
>      Set the powerplay debug flag to false for both Windows and Linux
>      to allow the calls to pplib. So we can retrieve the clock values
>      from powerplay instead of using default hardcoded values.
> 
>      Signed-off-by: Mikita Lipski <mikita.lipski at amd.com>
>      Reviewed-by: Charlene Liu <Charlene.Liu at amd.com>
>      Acked-by: Harry Wentland <harry.wentland at amd.com>
> 
> 
> Tom