[PATCH v8 10/39] drm/display: hdmi-state-helper: Sync SCDC state on hotplug

[Cristian Ciocaltea]

drm_atomic_helper_connector_hdmi_hotplug() does not currently
synchronize SCDC status on hotplug events, leaving the scrambler state
potentially inconsistent after (re)connect.

Hook drm_connector_hdmi_sync_scdc() into both the connect and disconnect
paths, replacing the existing TODOs around missing scrambler handling.

SCDC synchronization may require a CRTC reset, which in turn needs a
modeset acquire context for correct locking.  Therefore, extend
drm_atomic_helper_connector_hdmi_hotplug() and
drm_atomic_helper_connector_hdmi_update() to take a
drm_modeset_acquire_ctx argument.  Additionally, change their return
type from void to int, allowing propagation of errors, such as -EDEADLK
from lock contention.

Update existing callers to pass NULL for the acquire context, preserving
current behavior.

Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea at collabora.com>
---
 drivers/gpu/drm/display/drm_bridge_connector.c  |  3 ++-
 drivers/gpu/drm/display/drm_hdmi_state_helper.c | 28 +++++++++++++++++--------
 drivers/gpu/drm/vc4/vc4_hdmi.c                  |  2 +-
 include/drm/display/drm_hdmi_state_helper.h     |  6 ++++--
 4 files changed, 26 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/display/drm_bridge_connector.c b/drivers/gpu/drm/display/drm_bridge_connector.c
index 796069dbf1a1..46104506fe32 100644
--- a/drivers/gpu/drm/display/drm_bridge_connector.c
+++ b/drivers/gpu/drm/display/drm_bridge_connector.c
@@ -221,7 +221,8 @@ drm_bridge_connector_detect(struct drm_connector *connector, bool force)
 		status = detect->funcs->detect(detect, connector);
 
 		if (hdmi)
-			drm_atomic_helper_connector_hdmi_hotplug(connector, status);
+			drm_atomic_helper_connector_hdmi_hotplug(connector, status,
+								 NULL);
 
 		drm_bridge_connector_hpd_notify(connector, status);
 	} else {
diff --git a/drivers/gpu/drm/display/drm_hdmi_state_helper.c b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
index db76699093e8..69ccfbf123fe 100644
--- a/drivers/gpu/drm/display/drm_hdmi_state_helper.c
+++ b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
@@ -1198,18 +1198,20 @@ drm_atomic_helper_connector_hdmi_clear_audio_infoframe(struct drm_connector *con
 }
 EXPORT_SYMBOL(drm_atomic_helper_connector_hdmi_clear_audio_infoframe);
 
-static void
+static int
 drm_atomic_helper_connector_hdmi_update(struct drm_connector *connector,
-					enum drm_connector_status status)
+					enum drm_connector_status status,
+					struct drm_modeset_acquire_ctx *ctx)
 {
 	const struct drm_edid *drm_edid;
+	int ret = 0;
 
 	if (status == connector_status_disconnected) {
-		// TODO: also handle scramber, HDMI sink disconnected.
+		ret = drm_connector_hdmi_sync_scdc(connector, false, ctx);
 		drm_connector_hdmi_audio_plugged_notify(connector, false);
 		drm_edid_connector_update(connector, NULL);
 		drm_connector_cec_phys_addr_invalidate(connector);
-		return;
+		return ret;
 	}
 
 	if (connector->hdmi.funcs->read_edid)
@@ -1222,24 +1224,32 @@ drm_atomic_helper_connector_hdmi_update(struct drm_connector *connector,
 	drm_edid_free(drm_edid);
 
 	if (status == connector_status_connected) {
-		// TODO: also handle scramber, HDMI sink is now connected.
+		ret = drm_connector_hdmi_sync_scdc(connector, true, ctx);
 		drm_connector_hdmi_audio_plugged_notify(connector, true);
 		drm_connector_cec_phys_addr_set(connector);
 	}
+
+	return ret;
 }
 
 /**
  * drm_atomic_helper_connector_hdmi_hotplug - Handle the hotplug event for the HDMI connector
  * @connector: A pointer to the HDMI connector
  * @status: Connection status
+ * @ctx: Lock acquisition context to be used for resetting CRTC
  *
  * This function should be called as a part of the .detect() / .detect_ctx()
  * callbacks for all status changes.
+ *
+ * Returns:
+ * Zero on success, error code on failure.
+ * If @ctx is set, it might also return -EDEADLK.
  */
-void drm_atomic_helper_connector_hdmi_hotplug(struct drm_connector *connector,
-					      enum drm_connector_status status)
+int drm_atomic_helper_connector_hdmi_hotplug(struct drm_connector *connector,
+					     enum drm_connector_status status,
+					     struct drm_modeset_acquire_ctx *ctx)
 {
-	drm_atomic_helper_connector_hdmi_update(connector, status);
+	return drm_atomic_helper_connector_hdmi_update(connector, status, ctx);
 }
 EXPORT_SYMBOL(drm_atomic_helper_connector_hdmi_hotplug);
 
@@ -1254,6 +1264,6 @@ EXPORT_SYMBOL(drm_atomic_helper_connector_hdmi_hotplug);
  */
 void drm_atomic_helper_connector_hdmi_force(struct drm_connector *connector)
 {
-	drm_atomic_helper_connector_hdmi_update(connector, connector->status);
+	drm_atomic_helper_connector_hdmi_update(connector, connector->status, NULL);
 }
 EXPORT_SYMBOL(drm_atomic_helper_connector_hdmi_force);
diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index 74dce4be0c00..e165f604939b 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -375,7 +375,7 @@ static void vc4_hdmi_handle_hotplug(struct vc4_hdmi *vc4_hdmi,
 	 * the lock for now.
 	 */
 
-	drm_atomic_helper_connector_hdmi_hotplug(connector, status);
+	drm_atomic_helper_connector_hdmi_hotplug(connector, status, NULL);
 
 	if (status != connector_status_connected)
 		return;
diff --git a/include/drm/display/drm_hdmi_state_helper.h b/include/drm/display/drm_hdmi_state_helper.h
index 13375bd0f4ae..0619cd7c435e 100644
--- a/include/drm/display/drm_hdmi_state_helper.h
+++ b/include/drm/display/drm_hdmi_state_helper.h
@@ -7,6 +7,7 @@ struct drm_atomic_commit;
 struct drm_connector;
 struct drm_connector_state;
 struct drm_display_mode;
+struct drm_modeset_acquire_ctx;
 struct hdmi_audio_infoframe;
 
 enum drm_connector_status;
@@ -22,8 +23,9 @@ int drm_atomic_helper_connector_hdmi_update_audio_infoframe(struct drm_connector
 int drm_atomic_helper_connector_hdmi_clear_audio_infoframe(struct drm_connector *connector);
 int drm_atomic_helper_connector_hdmi_update_infoframes(struct drm_connector *connector,
 						       struct drm_atomic_commit *state);
-void drm_atomic_helper_connector_hdmi_hotplug(struct drm_connector *connector,
-					      enum drm_connector_status status);
+int drm_atomic_helper_connector_hdmi_hotplug(struct drm_connector *connector,
+					     enum drm_connector_status status,
+					     struct drm_modeset_acquire_ctx *ctx);
 void drm_atomic_helper_connector_hdmi_force(struct drm_connector *connector);
 
 enum drm_mode_status

-- 
2.54.0