drm: apple: dptx: Configure number of lanes for dptx-phy

Configuring the number of lanes is required for M2* desktop devices
either if those were not initialized by m1n1 or after hotplug.

Fixes: 07e4bfb ("drm: apple: dptx: Tidy up lane count handling")
Signed-off-by: Janne Grunau <j@jannau.net>

Author: jannau

drivers/gpu/drm/apple/dptxep.c

@@ -306,6 +306,9 @@ static int dptxport_call_set_active_lane_count(struct apple_epic_service *servic
 	case 0 ... 2:
 	case 4:
 		dptx->phy_ops.dp.lanes = lane_count;
+		// Use dptx phy index > 3 as indication for dptx-phy or
+		// lpdptx-phy and configure the number of lanes for those
+		dptx->phy_ops.dp.set_lanes = (dcp->dptx_phy > 3);
 		break;
 	default:
 		dev_err(dcp->dev, "set_active_lane_count: invalid lane count:%llu\n", lane_count);
@@ -314,6 +317,16 @@ static int dptxport_call_set_active_lane_count(struct apple_epic_service *servic
 		break;
 	}
 
+	if (dptx->phy_ops.dp.set_lanes) {
+		if (dptx->atcphy) {
+			ret = phy_configure(dptx->atcphy, &dptx->phy_ops);
+			if (ret)
+				return ret;
+		}
+		dptx->phy_ops.dp.set_lanes = 0;
+		dptx->lane_count = lane_count;
+	}
+
 	reply->retcode = cpu_to_le32(retcode);
 	reply->lane_count = cpu_to_le64(lane_count);