Patch "drm/probe-helper: Check epoch counter in output_poll_execute()" has been added to the 5.10-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    drm/probe-helper: Check epoch counter in output_poll_execute()

to the 5.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-probe-helper-check-epoch-counter-in-output_poll_.patch
and it can be found in the queue-5.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 870de0868b5b616eb32c0cc08c1047faf5e53d7b
Author: Noralf Trønnes <noralf@xxxxxxxxxxx>
Date:   Sat Mar 13 12:25:44 2021 +0100

    drm/probe-helper: Check epoch counter in output_poll_execute()
    
    [ Upstream commit dc659a4e852b591771fc2e5abb60f4455b0cf316 ]
    
    drm_helper_hpd_irq_event() checks the epoch counter to determine
    connector status change. This was introduced in
    commit 5186421cbfe2 ("drm: Introduce epoch counter to drm_connector").
    Do the same for output_poll_execute() so it can detect other changes
    beside connection status value changes.
    
    v2:
    - Add Fixes tag (Daniel)
    
    Fixes: 5186421cbfe2 ("drm: Introduce epoch counter to drm_connector")
    Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
    Signed-off-by: Noralf Trønnes <noralf@xxxxxxxxxxx>
    Link: https://patchwork.freedesktop.org/patch/msgid/20210313112545.37527-3-noralf@xxxxxxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c
index d6017726cc2a..e5432dcf6999 100644
--- a/drivers/gpu/drm/drm_probe_helper.c
+++ b/drivers/gpu/drm/drm_probe_helper.c
@@ -623,6 +623,7 @@ static void output_poll_execute(struct work_struct *work)
 	struct drm_connector_list_iter conn_iter;
 	enum drm_connector_status old_status;
 	bool repoll = false, changed;
+	u64 old_epoch_counter;
 
 	if (!dev->mode_config.poll_enabled)
 		return;
@@ -659,8 +660,9 @@ static void output_poll_execute(struct work_struct *work)
 
 		repoll = true;
 
+		old_epoch_counter = connector->epoch_counter;
 		connector->status = drm_helper_probe_detect(connector, NULL, false);
-		if (old_status != connector->status) {
+		if (old_epoch_counter != connector->epoch_counter) {
 			const char *old, *new;
 
 			/*
@@ -689,6 +691,9 @@ static void output_poll_execute(struct work_struct *work)
 				      connector->base.id,
 				      connector->name,
 				      old, new);
+			DRM_DEBUG_KMS("[CONNECTOR:%d:%s] epoch counter %llu -> %llu\n",
+				      connector->base.id, connector->name,
+				      old_epoch_counter, connector->epoch_counter);
 
 			changed = true;
 		}