forked from Minki/linux
5ee5a81df5
The plane allocator has been inherently racy since the beginning of the transition to atomic updates, as the allocator lock is released between free plane check (at .atomic_check() time) and the reservation (at .atomic_update() time). To fix it, create a new allocator solely based on the atomic plane states without keeping any external state and perform allocation in the .atomic_check() handler. The core idea is to replace the free planes bitmask with a collective knowledge based on the allocated hardware plane(s) for each KMS plane. The allocator then loops over all plane states to compute the free planes bitmask, allocates hardware planes based on that bitmask, and stores the result back in the plane states. For this to work we need to access the current state of planes not touched by the atomic update. To ensure that it won't be modified, we need to lock all planes using drm_atomic_get_plane_state(). This effectively serializes atomic updates from .atomic_check() up to completion, either when swapping the states if the check step has succeeded, or when freeing the states if the check step has failed. Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> |
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| host1x | ||
| ipu-v3 | ||
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| Makefile | ||