[PATCH xserver] modesetting: Fix page flipping under DRI 3.2.

[Daniel Stone]

On 3 April 2018 at 16:36, Mario Kleiner <mario.kleiner.de at gmail.com> wrote:
> Btw. another new problem, which i haven't had time to track down at
> all is that desktop composition under EGL seems to be totally broken.
> Tested on KUbuntu 16.0.4 LTS with xserver master + mesa master last
> thursday with whatever KDE Plasma 5 version ships with 16.04.
> Compositing with XRender accel or GLX + OpenGL 2/3 works fine. Could
> be modesetting, or glamor, or mesa.
>
> I get sometimes black screen, or sometimes massive corruption with
> pixel trash like if it displays random buffer contents from
> uninitialized buffers under modesetting-ddx + DRI3, on all kms
> drivers. Can anybody confirm this?

It is seeming like the compression support in the Intel driver has
regressed. If you edit mesa/src/mesa/drivers/dri/i965/intel_screen.c
and remove I915_FORMAT_MOD_Y_TILED_CCS from the supported_modifiers[]
array, does that resolve the issue?

Cheers,
Daniel