On Wed, Oct 21, 2020 at 9:32 AM Daniel Vetter <daniel.vetter@xxxxxxxx> 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. > > v2: Drop RFC, I think with amdgpu converted over to use > atomic_async_check/commit done in > > commit 674e78acae0dfb4beb56132e41cbae5b60f7d662 > Author: Nicholas Kazlauskas <nicholas.kazlauskas@xxxxxxx> > Date: Wed Dec 5 14:59:07 2018 -0500 > > drm/amd/display: Add fast path for cursor plane updates > > we don't have any driver anymore where we have userspace expecting > solid legacy cursor support _and_ they are using the atomic helpers in > their fully glory. So we can retire this. > > References: https://bugzilla.kernel.org/show_bug.cgi?id=199425 > Cc: mikita.lipski@xxxxxxx > Cc: Michel Dänzer <michel@xxxxxxxxxxx> > Cc: harry.wentland@xxxxxxx > Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx> This *completely* destroys fps when there is cursor movement, it would be a pretty bad regression, so nak BR, -R > --- > drivers/gpu/drm/drm_atomic_helper.c | 13 ------------- > 1 file changed, 13 deletions(-) > > diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c > index a7bcb4b4586c..549a31e6042c 100644 > --- a/drivers/gpu/drm/drm_atomic_helper.c > +++ b/drivers/gpu/drm/drm_atomic_helper.c > @@ -1481,13 +1481,6 @@ drm_atomic_helper_wait_for_vblanks(struct drm_device *dev, > int i, ret; > unsigned crtc_mask = 0; > > - /* > - * Legacy cursor ioctls are completely unsynced, and userspace > - * relies on that (by doing tons of cursor updates). > - */ > - if (old_state->legacy_cursor_update) > - return; > - > for_each_oldnew_crtc_in_state(old_state, crtc, old_crtc_state, new_crtc_state, i) { > if (!new_crtc_state->active) > continue; > @@ -2106,12 +2099,6 @@ int drm_atomic_helper_setup_commit(struct drm_atomic_state *state, > continue; > } > > - /* Legacy cursor updates are fully unsynced. */ > - if (state->legacy_cursor_update) { > - complete_all(&commit->flip_done); > - continue; > - } > - > if (!new_crtc_state->event) { > commit->event = kzalloc(sizeof(*commit->event), > GFP_KERNEL); > -- > 2.28.0 > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
