From: Boris Brezillon Date: Tue, 3 Jul 2018 07:50:18 +0000 (+0200) Subject: drm/vc4: Use wait_for_flip_done() instead of wait_for_vblanks() X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=184d3cf4f73896267340cf06acfa751fad4f8dd2;p=openwrt%2Fstaging%2Fblogic.git drm/vc4: Use wait_for_flip_done() instead of wait_for_vblanks() 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 Reviewed-by: Liviu Dudau Reviewed-by: Eric Anholt Link: https://patchwork.freedesktop.org/patch/msgid/20180703075022.15138-5-boris.brezillon@bootlin.com --- diff --git a/drivers/gpu/drm/vc4/vc4_kms.c b/drivers/gpu/drm/vc4/vc4_kms.c index 8a411e5f8776..91239b0a4fa0 100644 --- 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_atomic_state *state) 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);