drm/i915: Use the same vblank worker for atomic unpin

In case of legacy cursor update, the cursor VMA needs to be unpinned
only after vblank. This exceeds the lifetime of the whole atomic commit.

Any trick I attempted to keep the atomic commit alive didn't work, as
drm_atomic_helper_setup_commit() force throttles on any old commit that
wasn't cleaned up.

The only option remaining is to remove the plane from the atomic commit,
and use the same path as the legacy cursor update to clean the state
after vblank.

Changes since previous version:
- Call the memset for plane state immediately when scheduling vblank,
  this prevents a use-after-free in cursor cleanup.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240522053341.137592-4-maarten.lankhorst@linux.intel.com

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/display/intel_atomic_plane.h b/drivers/gpu/drm/i915/display/intel_atomic_plane.h
index 84541d97c67b..6c4fe3596465 100644
--- a/drivers/gpu/drm/i915/display/intel_atomic_plane.h
+++ b/drivers/gpu/drm/i915/display/intel_atomic_plane.h
@@ -71,5 +71,7 @@ void intel_plane_set_invisible(struct intel_crtc_state *crtc_state,
 			       struct intel_plane_state *plane_state);
 void intel_plane_helper_add(struct intel_plane *plane);
 bool intel_plane_needs_physical(struct intel_plane *plane);
+void intel_plane_init_cursor_vblank_work(struct intel_plane_state *old_plane_state,
+					 struct intel_plane_state *new_plane_state);
 
 #endif /* __INTEL_ATOMIC_PLANE_H__ */