drm/rockchip: cdn-dp: Use drm_connector_helper_hpd_irq_event()

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

diff --git a/drivers/gpu/drm/rockchip/cdn-dp-core.c b/drivers/gpu/drm/rockchip/cdn-dp-core.c
index b045389..f576b1a 100644 (file)
--- a/drivers/gpu/drm/rockchip/cdn-dp-core.c
+++ b/drivers/gpu/drm/rockchip/cdn-dp-core.c
@@ -947,9 +947,6 @@ 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);
@@ -1009,11 +1006,7 @@ 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,