[PATCH v10 21/69] drm/display: hdmi-state-helper: Pass acquire ctx to hotplug helpers

In preparation for supporting SCDC status synchronization on hotplug
events, extend drm_atomic_helper_connector_hdmi_hotplug() and
drm_atomic_helper_connector_hdmi_update() to take a struct
drm_modeset_acquire_ctx argument.  This will be used when a CRTC reset
is required.

Additionally, change their return type from void to int to allow
propagation of errors such as -EDEADLK caused by lock contention.

Update existing callers accordingly.  Note that in the VC4 case, the
return code is ignored, as it cannot fail: being in the .detect_ctx()
call path, the connection mutex is already held through ctx, and it
bails out early because the driver relies on a local SCDC
state-management implementation, and therefore does not yet expose the
scrambler capability through the common helpers.

Similarly, introduce drm_atomic_helper_connector_hdmi_force_ctx() as the
HDMI connector implementation of the .force_ctx() callback.  Since
migrating from the .force() callback is somewhat more involved, its
users will be migrated incrementally, after which
drm_atomic_helper_connector_hdmi_force() will be removed.

Tested-by: Diederik de Haas <[email protected]>  # NanoPC-T6 LTS, Rock 5B
Signed-off-by: Cristian Ciocaltea <[email protected]>
---
 drivers/gpu/drm/display/drm_bridge_connector.c  |  8 +++--
 drivers/gpu/drm/display/drm_hdmi_state_helper.c | 42 +++++++++++++++++++++----
 drivers/gpu/drm/vc4/vc4_hdmi.c                  |  2 +-
 include/drm/display/drm_hdmi_state_helper.h     |  8 +++--
 4 files changed, 49 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/display/drm_bridge_connector.c b/drivers/gpu/drm/display/drm_bridge_connector.c
index 80b33d4f6b38..e78efccb7757 100644
--- a/drivers/gpu/drm/display/drm_bridge_connector.c
+++ b/drivers/gpu/drm/display/drm_bridge_connector.c
@@ -286,12 +286,16 @@ static int drm_bridge_connector_detect_ctx(struct drm_connector *connector,
 	struct drm_bridge *detect = bridge_connector->bridge_detect;
 	struct drm_bridge *hdmi = bridge_connector->bridge_hdmi;
 	enum drm_connector_status status;
+	int ret;
 
 	if (detect) {
 		status = detect->funcs->detect(detect, connector);
 
-		if (hdmi)
-			drm_atomic_helper_connector_hdmi_hotplug(connector, status);
+		if (hdmi) {
+			ret = drm_atomic_helper_connector_hdmi_hotplug(connector, ctx, status);
+			if (ret == -EDEADLK)
+				return ret;
+		}
 
 		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 92be6278ea44..4a93c279c9a7 100644
--- a/drivers/gpu/drm/display/drm_hdmi_state_helper.c
+++ b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
@@ -1199,8 +1199,9 @@ 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,
+					struct drm_modeset_acquire_ctx *ctx,
 					enum drm_connector_status status)
 {
 	const struct drm_edid *drm_edid;
@@ -1210,7 +1211,7 @@ drm_atomic_helper_connector_hdmi_update(struct drm_connector *connector,
 		drm_connector_hdmi_audio_plugged_notify(connector, false);
 		drm_edid_connector_update(connector, NULL);
 		drm_connector_cec_phys_addr_invalidate(connector);
-		return;
+		return 0;
 	}
 
 	if (connector->hdmi.funcs->read_edid)
@@ -1227,20 +1228,28 @@ drm_atomic_helper_connector_hdmi_update(struct drm_connector *connector,
 		drm_connector_hdmi_audio_plugged_notify(connector, true);
 		drm_connector_cec_phys_addr_set(connector);
 	}
+
+	return 0;
 }
 
 /**
  * drm_atomic_helper_connector_hdmi_hotplug - Handle the hotplug event for the HDMI connector
  * @connector: A pointer to the HDMI connector
+ * @ctx: Lock acquisition context to be used for resetting CRTC
  * @status: Connection status
  *
  * 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,
+					     struct drm_modeset_acquire_ctx *ctx,
+					     enum drm_connector_status status)
 {
-	drm_atomic_helper_connector_hdmi_update(connector, status);
+	return drm_atomic_helper_connector_hdmi_update(connector, ctx, status);
 }
 EXPORT_SYMBOL(drm_atomic_helper_connector_hdmi_hotplug);
 
@@ -1255,6 +1264,27 @@ 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, NULL, connector->status);
 }
 EXPORT_SYMBOL(drm_atomic_helper_connector_hdmi_force);
+
+/**
+ * drm_atomic_helper_connector_hdmi_force_ctx - HDMI Connector implementation
+ * of the force_ctx callback
+ * @connector: A pointer to the HDMI connector
+ * @ctx: Lock acquisition context to be used for resetting CRTC
+ *
+ * This function implements the .force_ctx() callback for the HDMI connectors.
+ * It can either be used directly as the callback or should be called from
+ * within the .force_ctx() callback implementation to maintain the HDMI-specific
+ * connector's data.
+ *
+ * Returns:
+ * Zero on success, error code on failure, including -EDEADLK.
+ */
+int drm_atomic_helper_connector_hdmi_force_ctx(struct drm_connector *connector,
+					       struct drm_modeset_acquire_ctx *ctx)
+{
+	return drm_atomic_helper_connector_hdmi_update(connector, ctx, connector->status);
+}
+EXPORT_SYMBOL(drm_atomic_helper_connector_hdmi_force_ctx);
diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index 72ff95ca97de..7f613f912368 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, ctx, status);
 
 	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..ae4fff82c3fb 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;
@@ -22,9 +23,12 @@ 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,
+					     struct drm_modeset_acquire_ctx *ctx,
+					     enum drm_connector_status status);
 void drm_atomic_helper_connector_hdmi_force(struct drm_connector *connector);
+int drm_atomic_helper_connector_hdmi_force_ctx(struct drm_connector *connector,
+					       struct drm_modeset_acquire_ctx *ctx);
 
 enum drm_mode_status
 drm_hdmi_connector_mode_valid(struct drm_connector *connector,

-- 
2.55.0