modesetting TearFree / VSYNC aware rotation pageflipping

[Martin Peres]

On 03/10/2018 17:36, Michel Dänzer wrote:
> On 2018-10-03 4:22 p.m., Carsten Behling wrote:
>>
>>> TearFree uses separate dedicated scanout buffers, to which the "main"
>>> buffer contents are copied on demand.
>>>
>>> Originally, these three things (DRI page flipping, rotation and
>>> TearFree) were separate and mutually exclusive. However, the
>>> amdgpu/radeon drivers support all of them the same time these days; this
>>> still requires an extra copy in some cases, but that could be eliminated
>>> at least in the non-rotated DRI page flipping case.
>>>
>>> https://gitlab.freedesktop.org/xorg/xserver/merge_requests/24 has the
>>> start of TearFree support for the modesetting driver, but it's still
>>> mutually exclusive with rotation (DRI3 page flipping should work with
>>> TearFree, but may still exhibit tearing if the client/user disables
>>> sync-to-vblank).
>>
>> Couldn't we extend modesetting in addition to Martin's TearFree patch the
>> same way you did here for Radeon?:
>>
>> https://cgit.freedesktop.org/xorg/driver/xf86-video-ati/commit/?id=798c4fd16d339b1ad5fd729cc884be084c60e38b
> 
> Yeah, something like that would be needed.
> 

Carsten,

Would you like to add support for it on top of my branch? I am a bit
swamped but I could be convinced to help you on this if needed :)

Martin