[PATCH v11 23/74] 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.
Note that per .detect_ctx() contract, implementations shall return a
drm_connector_status value or -EDEADLK, nothing else.  Therefore, handle
deadlocks and just report any other errors.  For consistency, also
report the errors from drm_edid_connector_update().

Tested-by: Maud Spierings <maud_spierings at hotmail.com>
Tested-by: Diederik de Haas <diederik at cknow-tech.com>  # NanoPC-T6 LTS, Rock 5B
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea at collabora.com>
---
 drivers/gpu/drm/display/drm_hdmi_state_helper.c | 34 ++++++++++++++++++++++---
 1 file changed, 31 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/display/drm_hdmi_state_helper.c b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
index 8045b1d17d6e..1e269b203b98 100644
--- a/drivers/gpu/drm/display/drm_hdmi_state_helper.c
+++ b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
@@ -1362,12 +1362,29 @@ drm_atomic_helper_connector_hdmi_update(struct drm_connector *connector,
 					enum drm_connector_status status)
 {
 	const struct drm_edid *drm_edid;
+	int ret;
 
 	if (status == connector_status_disconnected) {
-		// TODO: also handle scramber, HDMI sink disconnected.
+		/*
+		 * .detect_ctx() can only ever return a drm_connector_status or
+		 * -EDEADLK. Handle deadlocks, and report any !EDEADLK error.
+		 */
+		ret = drm_connector_hdmi_sync_scdc(connector, false, ctx);
+		if (ret) {
+			if (ret == -EDEADLK)
+				return ret;
+
+			drm_warn(connector->dev, "Ignored SCDC sync error: %d\n", ret);
+		}
+
 		drm_connector_hdmi_audio_plugged_notify(connector, false);
-		drm_edid_connector_update(connector, NULL);
+
+		ret = drm_edid_connector_update(connector, NULL);
+		if (ret)
+			drm_warn(connector->dev, "Ignored EDID update error: %d\n", ret);
+
 		drm_connector_cec_phys_addr_invalidate(connector);
+
 		return 0;
 	}
 
@@ -1381,7 +1398,18 @@ 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.
+		/*
+		 * .detect_ctx() can only ever return a drm_connector_status or
+		 * -EDEADLK. Handle deadlocks, and report any !EDEADLK error.
+		 */
+		ret = drm_connector_hdmi_sync_scdc(connector, true, ctx);
+		if (ret) {
+			if (ret == -EDEADLK)
+				return ret;
+
+			drm_warn(connector->dev, "Ignored SCDC sync error: %d\n", ret);
+		}
+
 		drm_connector_hdmi_audio_plugged_notify(connector, true);
 		drm_connector_cec_phys_addr_set(connector);
 	}

-- 
2.55.0