From 16f9ca03b3a7794f3b621769ada91aa578f1b4d5 Mon Sep 17 00:00:00 2001
From: Kenny Levinsen <kl@kl.wtf>
Date: Tue, 15 Oct 2024 16:21:49 +0200
Subject: [PATCH 1/2] desktop/output: Wait for all pageflips to clear

To allow a non-blocking modeset to succeed, we need to wait for all
pageflips to clear first.
---
 sway/desktop/output.c | 59 ++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 58 insertions(+), 1 deletion(-)

diff --git a/sway/desktop/output.c b/sway/desktop/output.c
index a4eaa4b334..c8fa17b641 100644
--- a/sway/desktop/output.c
+++ b/sway/desktop/output.c
@@ -391,12 +391,69 @@ void update_output_manager_config(struct sway_server *server) {
 	ipc_event_output();
 }
 
+// Placeholder while all render tasks clear up
+static void handle_frame_nop(struct wl_listener *listener, void *user_data) {}
+
+static void handle_frame_clear(struct wl_listener *listener, void *user_data) {
+	struct sway_output *output = wl_container_of(listener, output, frame);
+	output->frame.notify = handle_frame_nop;
+
+	sway_log(SWAY_DEBUG, "Render task for %s cleared", output->wlr_output->name);
+
+	wl_list_for_each(output, &root->all_outputs, link) {
+		if (output == root->fallback_output) {
+			continue;
+		}
+		if (output->frame.notify != handle_frame_nop) {
+			return;
+		}
+	}
+
+	// All done!
+	sway_log(SWAY_DEBUG, "All render tasks cleared, modestting");
+	wl_list_for_each(output, &root->all_outputs, link) {
+		if (output == root->fallback_output) {
+			continue;
+		}
+		output->frame.notify = handle_frame;
+	}
+	apply_stored_output_configs();
+}
+
 static int timer_modeset_handle(void *data) {
 	struct sway_server *server = data;
 	wl_event_source_remove(server->delayed_modeset);
 	server->delayed_modeset = NULL;
 
-	apply_stored_output_configs();
+	bool wait = false;
+	struct sway_output *output;
+	wl_list_for_each(output, &root->all_outputs, link) {
+		if (output == root->fallback_output) {
+			continue;
+		}
+		if (output->wlr_output->frame_pending) {
+			output->frame.notify = handle_frame_clear;
+			wait = true;
+			sway_log(SWAY_DEBUG, "Awaiting render task on %s", output->wlr_output->name);
+		} else {
+			output->frame.notify = handle_frame_nop;
+		}
+	}
+
+	if (!wait) {
+		// Nothing to wait for, go ahead
+		sway_log(SWAY_DEBUG, "No render tasks to wait for, modesetting");
+		wl_list_for_each(output, &root->all_outputs, link) {
+			if (output == root->fallback_output) {
+				continue;
+			}
+			output->frame.notify = handle_frame;
+		}
+		apply_stored_output_configs();
+		return 0;
+	}
+
+
 	return 0;
 }
 

From 7a50d03d3b158fbb9be909f6ed371a24569fbd00 Mon Sep 17 00:00:00 2001
From: Kenny Levinsen <kl@kl.wtf>
Date: Tue, 15 Oct 2024 16:43:57 +0200
Subject: [PATCH 2/2] WIP silence error that happens a lot after modeset

---
 sway/desktop/output.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sway/desktop/output.c b/sway/desktop/output.c
index c8fa17b641..5996a6bd05 100644
--- a/sway/desktop/output.c
+++ b/sway/desktop/output.c
@@ -296,7 +296,7 @@ static int output_repaint_timer_handler(void *data) {
 	}
 
 	if (!wlr_output_commit_state(output->wlr_output, &pending)) {
-		sway_log(SWAY_ERROR, "Page-flip failed on output %s", output->wlr_output->name);
+		// sway_log(SWAY_ERROR, "Page-flip failed on output %s", output->wlr_output->name);
 	}
 	wlr_output_state_finish(&pending);
 	return 0;