From cdd9a60f72e1067e3b7b0ad1846e83f489e51be2 Mon Sep 17 00:00:00 2001
From: Rouven Czerwinski <rouven@czerwinskis.de>
Date: Tue, 17 Aug 2021 20:50:48 +0200
Subject: [PATCH] Revert "backend/drm: Check if output is enabled before
 sending frame event"

This reverts commit 85757665e6e1393773b36282aa244feb10b7a5fe.

We now check if the output is enabled within wlr_output_send_frame, no
need to handle this explicitly in the DRM backend. This also fixes a
race which was introduced with this commit: if we schedule the flip,
disable and commit the output before the flip happens,
output.frame_pending will not be reset to false. We than always fail to
enable the output subsequently:

      00:07:13.276 [INFO] [sway/commands.c:257] Handling command 'output DP-2 enable'
      00:07:13.276 [DEBUG] [sway/commands.c:428] Subcommand: enable
      00:07:13.276 [DEBUG] [sway/config/output.c:204] Merging on top of existing output config
      00:07:13.276 [DEBUG] [sway/config/output.c:227] Config stored for output DP-2 (enabled: 1) (-1x-1@-1.000000Hz position 0,0 scale -1.000000 subpixel unknown transform -1) (bg /home/phoenix/Pictures/Wallpapers/mine/oper.jpg fill) (dpms 1) (max render time: -1)
      00:07:13.276 [DEBUG] [sway/config/output.c:351] Turning on output DP-2
      00:07:13.276 [DEBUG] [sway/config/output.c:360] Set preferred mode
      00:07:13.276 [DEBUG] [wlr] [backend/drm/drm.c:465] connector DP-2: Can't enable an output without a buffer
      00:07:13.276 [DEBUG] [wlr] [types/wlr_output.c:689] Attaching empty buffer to output for modeset
      00:07:13.277 [DEBUG] [sway/config/output.c:329] Output DPI: 162.560000x161.364706
      00:07:13.277 [DEBUG] [sway/config/output.c:400] Auto-detected output scale: 1.000000
      00:07:13.277 [DEBUG] [sway/config/output.c:430] Committing output DP-2
      00:07:13.277 [DEBUG] [wlr] [types/wlr_output.c:729] Tried to commit a buffer while a frame is pending

since the basic_output_test will always fail.
Reset frame_pending to false even if the output has been disabled in the
meantime.

Fixes https://github.com/swaywm/wlroots/issues/3109
---
 backend/drm/drm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/backend/drm/drm.c b/backend/drm/drm.c
index 480b18b6..95b27f04 100644
--- a/backend/drm/drm.c
+++ b/backend/drm/drm.c
@@ -1521,7 +1521,7 @@ static void handle_page_flip(int fd, unsigned seq,
 	};
 	wlr_output_send_present(&conn->output, &present_event);
 
-	if (drm->session->active && conn->output.enabled) {
+	if (drm->session->active) {
 		wlr_output_send_frame(&conn->output);
 	}
 }