From 8d454e1e34988868b45693c8e2178c70bd19ad2f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?F=C3=A9lix=20Poisot?= <felix@lhfblc.fr>
Date: Fri, 14 Mar 2025 12:16:21 +0000
Subject: [PATCH] output/drm: don't use OUT_FENCE_PTR

The returned fence is not required to be signalled at the earliest
possible time. It is not intended to replace the drm flip event, and is
expected to be signalled only much later
---
 backend/drm/atomic.c      | 30 ------------------------------
 backend/drm/drm.c         |  1 -
 backend/drm/libliftoff.c  |  4 ----
 include/backend/drm/drm.h |  2 +-
 4 files changed, 1 insertion(+), 36 deletions(-)

diff --git a/backend/drm/atomic.c b/backend/drm/atomic.c
index f12c56907..daa8ba9bf 100644
--- a/backend/drm/atomic.c
+++ b/backend/drm/atomic.c
@@ -424,17 +424,6 @@ void drm_atomic_connector_apply_commit(struct wlr_drm_connector_state *state) {
 	if (state->primary_in_fence_fd >= 0) {
 		close(state->primary_in_fence_fd);
 	}
-	if (state->out_fence_fd >= 0) {
-		// TODO: error handling
-		if (crtc->primary->current_release_timeline != NULL) {
-			wlr_drm_syncobj_timeline_import_sync_file(crtc->primary->current_release_timeline,
-				crtc->primary->current_release_point, state->out_fence_fd);
-			wlr_drm_syncobj_timeline_unref(crtc->primary->current_release_timeline);
-			crtc->primary->current_release_timeline = NULL;
-			crtc->primary->current_release_point = 0;
-		}
-		close(state->out_fence_fd);
-	}
 
 	conn->colorspace = state->colorspace;
 }
@@ -452,9 +441,6 @@ void drm_atomic_connector_rollback_commit(struct wlr_drm_connector_state *state)
 	if (state->primary_in_fence_fd >= 0) {
 		close(state->primary_in_fence_fd);
 	}
-	if (state->out_fence_fd >= 0) {
-		close(state->out_fence_fd);
-	}
 }
 
 static void plane_disable(struct atomic *atom, struct wlr_drm_plane *plane) {
@@ -562,19 +548,6 @@ static void set_plane_in_fence_fd(struct atomic *atom,
 	atomic_add(atom, plane->id, plane->props.in_fence_fd, sync_file_fd);
 }
 
-static void set_crtc_out_fence_ptr(struct atomic *atom, struct wlr_drm_crtc *crtc,
-		int *fd_ptr) {
-	if (!crtc->props.out_fence_ptr) {
-		wlr_log(WLR_ERROR,
-			"CRTC %"PRIu32" is missing the OUT_FENCE_PTR property",
-			crtc->id);
-		atom->failed = true;
-		return;
-	}
-
-	atomic_add(atom, crtc->id, crtc->props.out_fence_ptr, (uintptr_t)fd_ptr);
-}
-
 static void atomic_connector_add(struct atomic *atom,
 		struct wlr_drm_connector_state *state, bool modeset) {
 	struct wlr_drm_connector *conn = state->connector;
@@ -623,9 +596,6 @@ static void atomic_connector_add(struct atomic *atom,
 		if (state->primary_in_fence_fd >= 0) {
 			set_plane_in_fence_fd(atom, crtc->primary, state->primary_in_fence_fd);
 		}
-		if (state->base->committed & WLR_OUTPUT_STATE_SIGNAL_TIMELINE) {
-			set_crtc_out_fence_ptr(atom, crtc, &state->out_fence_fd);
-		}
 		if (crtc->cursor) {
 			if (drm_connector_is_cursor_visible(conn)) {
 				struct wlr_fbox cursor_src = {
diff --git a/backend/drm/drm.c b/backend/drm/drm.c
index 7cfea5a14..d2f75f71f 100644
--- a/backend/drm/drm.c
+++ b/backend/drm/drm.c
@@ -669,7 +669,6 @@ static void drm_connector_state_init(struct wlr_drm_connector_state *state,
 		.base = base,
 		.active = output_pending_enabled(&conn->output, base),
 		.primary_in_fence_fd = -1,
-		.out_fence_fd = -1,
 	};
 
 	struct wlr_output_mode *mode = conn->output.current_mode;
diff --git a/backend/drm/libliftoff.c b/backend/drm/libliftoff.c
index 12761afd4..333beacad 100644
--- a/backend/drm/libliftoff.c
+++ b/backend/drm/libliftoff.c
@@ -352,10 +352,6 @@ static bool add_connector(drmModeAtomicReq *req,
 			liftoff_layer_set_property(crtc->liftoff_composition_layer,
 				"IN_FENCE_FD", state->primary_in_fence_fd);
 		}
-		if (state->base->committed & WLR_OUTPUT_STATE_SIGNAL_TIMELINE) {
-			ok = ok && add_prop(req, crtc->id, crtc->props.out_fence_ptr,
-				(uintptr_t)&state->out_fence_fd);
-		}
 
 		if (state->base->committed & WLR_OUTPUT_STATE_LAYERS) {
 			for (size_t i = 0; i < state->base->layers_len; i++) {
diff --git a/include/backend/drm/drm.h b/include/backend/drm/drm.h
index e07c16efe..a8c5e077a 100644
--- a/include/backend/drm/drm.h
+++ b/include/backend/drm/drm.h
@@ -160,7 +160,7 @@ struct wlr_drm_connector_state {
 	uint32_t mode_id;
 	uint32_t gamma_lut;
 	uint32_t fb_damage_clips;
-	int primary_in_fence_fd, out_fence_fd;
+	int primary_in_fence_fd;
 	bool vrr_enabled;
 	uint32_t colorspace;
 	uint32_t hdr_output_metadata;