[PATCH] drm/amdgpu: For virtual_display feature, define a variable for vblank count of cpu vsync timer.

[Michel Dänzer]

On 16/08/16 12:49 PM, Deng, Emily wrote:
> Hi Michel, Thanks, I still couldn't see the issue that use a variable
> to calculate the vblank count when vsync timer interrupt occurs. I
> just think it only emulates the hardware behavior. And the code
> change will only in virtual display files which won't touch drm
> layer. I incline to not modify the code in drm layer or amdgpu other
> codes, because it may lead to other issues .

I see it basically the other way around: We are currently pretending to
the DRM core code that we have a reliable hardware vblank counter and
timing even in the virtual DCE case, when we really don't. We should
stop pretending and instead communicate the lack of these hardware
facilities in the virtual DCE case as intended, otherwise we'll probably
run into issues sooner or later.


-- 
Earthling Michel Dänzer               |               http://www.amd.com
Libre software enthusiast             |             Mesa and X developer