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authorSimon Ser <contact@emersion.fr>2022-05-27 13:21:55 +0200
committerSimon Ser <contact@emersion.fr>2022-06-01 21:16:02 +0200
commitacc6d94db048118e7e910d7812431dfb27b2d769 (patch)
tree3d4c0f20150501c0f741673257887330f0a55a04
parente383c1f1db37c6d2de8f070603a89230f876bc80 (diff)
backend/drm: make commits without a buffer blocking
The wlr_output API requires compositors to wait for wlr_output.frame before submitting a new buffer. However, compositors can perform a commit which doesn't involve a buffer anytime. If the commit is a modeset, we set DRM_MODE_ATOMIC_ALLOW_MODESET and block until the commit is done. If it isn't, we currently always perform a non-blocking commit. This is an issue because a previous page-flip might still be in flight kernel-side, returning EBUSY. Fix this by using blocking commits when a buffer isn't submitted by the compositor. Closes: https://github.com/swaywm/sway/issues/6962 References: https://gitlab.freedesktop.org/wlroots/wlroots/-/issues/2239
-rw-r--r--backend/drm/atomic.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/backend/drm/atomic.c b/backend/drm/atomic.c
index cacb8e87..1d4f9df4 100644
--- a/backend/drm/atomic.c
+++ b/backend/drm/atomic.c
@@ -264,7 +264,12 @@ static bool atomic_crtc_commit(struct wlr_drm_connector *conn,
}
if (modeset) {
flags |= DRM_MODE_ATOMIC_ALLOW_MODESET;
- } else if (!test_only) {
+ } else if (!test_only && (state->base->committed & WLR_OUTPUT_STATE_BUFFER)) {
+ // The wlr_output API requires non-modeset commits with a new buffer to
+ // wait for the frame event. However compositors often perform
+ // non-modesets commits without a new buffer without waiting for the
+ // frame event. In that case we need to make the KMS commit blocking,
+ // otherwise the kernel will error out with EBUSY.
flags |= DRM_MODE_ATOMIC_NONBLOCK;
}