drm/probe-helper: Cancel previous job before starting new one

[ Upstream commit a8e47884f1906cd7440fafa056adc8817568e73e ]

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
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c
index adbabf16c07b2999bca60ad0b7a0a3ee4a0ee9b8..f76eced3ff94faa999194f1b3e081f87d7078a11 100644 (file)
--- a/drivers/gpu/drm/drm_probe_helper.c
+++ b/drivers/gpu/drm/drm_probe_helper.c
@@ -465,8 +465,9 @@ retry:
                 */
                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. */