Isn't the high bandwidth path for HDMI uni-directional? Not half-duplex, but actually one way only, as in the receiver doesn't have the hardware to transmit bac

Isn't the high bandwidth path for HDMI uni-directional? Not half-duplex, but actually one way only, as in the receiver doesn't have the hardware to transmit back (on those lines). I'm not terribly knowledgeable about HDMI but I think that's basically the case, someone please correct me or elaborate if they know more. There are some other bi-directional communications channels for control and other features like DRM (HDCP) or even Fast Ethernet but they don't get nearly that much bandwidth.