[PATCH 5.15 441/620] drm/rockchip: cdn-dp: Use drm_connector_helper_hpd_irq_event()

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

5.15-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Thomas Zimmermann <tzimmermann@suse.de>

[ Upstream commit 666e1960464140cc4bc9203c203097e70b54c95a ]

The code for detecting and updating the connector status in
cdn_dp_pd_event_work() has a number of problems.

- It does not aquire the locks to call the detect helper and update
the connector status. These are struct drm_mode_config.connection_mutex
and struct drm_mode_config.mutex.

- It does not use drm_helper_probe_detect(), which helps with the
details of locking and detection.

- It uses the connector's status field to determine a change to
the connector status. The epoch_counter field is the correct one. The
field signals a change even if the connector status' value did not
change.

Replace the code with a call to drm_connector_helper_hpd_irq_event(),
which fixes all these problems.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: 81632df69772 ("drm/rockchip: cdn-dp: do not use drm_helper_hpd_irq_event")
Cc: Chris Zhong <zyw@rock-chips.com>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Sandy Huang <hjc@rock-chips.com>
Cc: "Heiko Stübner" <heiko@sntech.de>
Cc: Andy Yan <andy.yan@rock-chips.com>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-rockchip@lists.infradead.org
Cc: <stable@vger.kernel.org> # v4.11+
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20241105133848.480407-1-tzimmermann@suse.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/rockchip/cdn-dp-core.c | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/rockchip/cdn-dp-core.c b/drivers/gpu/drm/rockchip/cdn-dp-core.c
index b9ef35a35c857..af1e361da8df9 100644
--- a/drivers/gpu/drm/rockchip/cdn-dp-core.c
+++ b/drivers/gpu/drm/rockchip/cdn-dp-core.c
@@ -916,9 +916,6 @@ static void cdn_dp_pd_event_work(struct work_struct *work)
 {
 	struct cdn_dp_device *dp = container_of(work, struct cdn_dp_device,
 						event_work);
-	struct drm_connector *connector = &dp->connector;
-	enum drm_connector_status old_status;
-
 	int ret;
 
 	mutex_lock(&dp->lock);
@@ -980,11 +977,7 @@ static void cdn_dp_pd_event_work(struct work_struct *work)
 
 out:
 	mutex_unlock(&dp->lock);
-
-	old_status = connector->status;
-	connector->status = connector->funcs->detect(connector, false);
-	if (old_status != connector->status)
-		drm_kms_helper_hotplug_event(dp->drm_dev);
+	drm_connector_helper_hpd_irq_event(&dp->connector);
 }
 
 static int cdn_dp_pd_event(struct notifier_block *nb,
-- 
2.39.5