[Intel-gfx] [PATCH 4/7] drm/i915/skl: New ddb allocation algorithm

[Mahesh Kumar]

Hi,
In this series, I'm not equalizing watermarks among planes of all 
CRTC's, these patches equalizing it only among Planes of single CRTC 
from DDB pool allocated for that CRTC, which doesn't require wait_for_vblank
So it'll not affect the FPS.

On Wednesday 31 August 2016 07:08 PM, Maarten Lankhorst wrote:
> Hey,
>
> Op 29-08-16 om 14:35 schreef Kumar, Mahesh:
>> This patch implements new DDB allocation algorithm as per HW team
>> suggestion. This algo takecare of scenario where we allocate less DDB
>> for the planes with lower relative pixel rate, but they require more DDB
>> to work.
>> It also takes care of enabling same watermark level for each
>> plane, for efficient power saving.
> Patch 2 and 3 look ok, I'm not a watermark expert though. :)
>
> To be honest, skylake watermarks are very complicated with all the interdepencies. I can understand this helps,
> but if you do separate per crtc atomic commits, it doesn't help a update for crtc1 may introduce a vblank wait on crtc2 and the other way around. This will drop the framerate to half.
>
> Is there no way around it?
>
> ~Maarten