From: Boris Brezillon <boris.brezillon@bootlin.com>
Date: Tue, 3 Jul 2018 09:50:18 +0200
Subject: drm/vc4: Use wait_for_flip_done() instead of wait_for_vblanks()
Git-commit: 184d3cf4f73896267340cf06acfa751fad4f8dd2
Patch-mainline: v4.19-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166
drm_atomic_helper_wait_for_vblanks() assumes the CRTC will continuously
generate VBLANK events and the vblank counter will keep increasing.
While this work for a regular pipeline, it doesn't when you have the
CRTC is feeding the transposer block, because this block works in
oneshot mode, and, by the time we reach
drm_atomic_helper_wait_for_vblanks() the only VBLANK event might have
already been sent and the VBLANK counter will stay unchanged, thus
triggering a timeout.
Luckily, we can replace the drm_atomic_helper_wait_for_vblanks() call
by drm_atomic_helper_wait_for_flip_done() because the only thing we
want to check when calling drm_atomic_helper_wait_for_vblanks() from
vc4_atomic_complete_commit() is that new FBs are in use and the old
ones can be safely released.
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20180703075022.15138-5-boris.brezillon@bootlin.com
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
drivers/gpu/drm/vc4/vc4_kms.c | 11 +----------
1 file changed, 1 insertion(+), 10 deletions(-)
--- a/drivers/gpu/drm/vc4/vc4_kms.c
+++ b/drivers/gpu/drm/vc4/vc4_kms.c
@@ -153,18 +153,9 @@ vc4_atomic_complete_commit(struct drm_at
drm_atomic_helper_commit_modeset_enables(dev, state);
- /* Make sure that drm_atomic_helper_wait_for_vblanks()
- * actually waits for vblank. If we're doing a full atomic
- * modeset (as opposed to a vc4_update_plane() short circuit),
- * then we need to wait for scanout to be done with our
- * display lists before we free it and potentially reallocate
- * and overwrite the dlist memory with a new modeset.
- */
- state->legacy_cursor_update = false;
-
drm_atomic_helper_commit_hw_done(state);
- drm_atomic_helper_wait_for_vblanks(dev, state);
+ drm_atomic_helper_wait_for_flip_done(dev, state);
drm_atomic_helper_cleanup_planes(dev, state);