[PATCH xf86-video-ati 5/6] Make all active CRTCs scan out an all-black framebuffer in LeaveVT

[Emil Velikov]

Hi Michel,

On 28 August 2017 at 10:23, Michel Dänzer <michel at daenzer.net> wrote:
> From: Michel Dänzer <michel.daenzer at amd.com>
>
> And destroy all other FBs. This is so that other DRM masters can only
> get access to this all-black FB, not to any other FB we created, while
> we're switched away and not DRM master.
>
Isn't the issue applicable overall - be that in X, wayland compositors, other?

IIRC the vmwgfx's kernel driver, which has extra locking [1] in order
to address that.
Would a similar approach like that be applicable for radeon/amdgpu?

I'm not saying that this is bad/not needed. Just wondering on a
"perfect" long term solution.
That is, unless I've lost the plot and the two are completely unrelated.

Thanks
Emil

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c?h=v4.13-rc7#n1054