Re: [PATCH] drm/atomic-helpers: remove legacy_cursor_update hacks

Hi,

On Thu, Feb 16, 2023 at 12:12:13PM +0100, Daniel Vetter wrote:

The stuff never really worked, and leads to lots of fun because it
out-of-order frees atomic states. Which upsets KASAN, among other
things.

For async updates we now have a more solid solution with the
->atomic_async_check and ->atomic_async_commit hooks. Support for that
for msm and vc4 landed. nouveau and i915 have their own commit
routines, doing something similar.

For everyone else it's probably better to remove the use-after-free
bug, and encourage folks to use the async support instead. The
affected drivers which register a legacy cursor plane and don't either
use the new async stuff or their own commit routine are: amdgpu,
atmel, mediatek, qxl, rockchip, sti, sun4i, tegra, virtio, and vmwgfx.

Inspired by an amdgpu bug report.

Thanks for submitting that patch. It's been in the downstream RPi tree
for a while, so I'd really like it to be merged eventually :)

Acked-by: Maxime Ripard <redacted>

Maxime