From a8e47884f1906cd7440fafa056adc8817568e73e Mon Sep 17 00:00:00 2001
From: Dom Cobley <popcornmix@gmail.com>
Date: Fri, 27 Jan 2023 16:40:52 +0100
Subject: [PATCH] drm/probe-helper: Cancel previous job before starting new one
Git-commit: a8e47884f1906cd7440fafa056adc8817568e73e
Patch-mainline: v6.4-rc1
References: git-fixes

Currently we schedule a call to output_poll_execute from
drm_kms_helper_poll_enable for 10s in future. Later we try to replace
that in drm_helper_probe_single_connector_modes with a 0s schedule with
delayed_event set.

But as there is already a job in the queue this fails, and the immediate
job we wanted with delayed_event set doesn't occur until 10s later.

And that call acts as if connector state has changed, reprobing modes.
This has a side effect of waking up a display that has been blanked.

Make sure we cancel the old job before submitting the immediate one.

Fixes: 162b6a57ac50 ("drm/probe-helper: don't lose hotplug event")
Acked-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Dom Cobley <popcornmix@gmail.com>
[maxime: Switched to mod_delayed_work]
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20230127154052.452524-1-maxime@cerno.tech
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/drm_probe_helper.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c
index 8127be134c39..2fb9bf901a2c 100644
--- a/drivers/gpu/drm/drm_probe_helper.c
+++ b/drivers/gpu/drm/drm_probe_helper.c
@@ -590,8 +590,9 @@ int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
 		 */
 		dev->mode_config.delayed_event = true;
 		if (dev->mode_config.poll_enabled)
-			schedule_delayed_work(&dev->mode_config.output_poll_work,
-					      0);
+			mod_delayed_work(system_wq,
+					 &dev->mode_config.output_poll_work,
+					 0);
 	}
 
 	/* Re-enable polling in case the global poll config changed. */
-- 
2.35.3