A bad link in MST is not retrained. Please also consider MST. The issue ticket is https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/10902. if (intel_dp->is_mst) { /* * If we are in MST mode then this connector * won't appear connected or have anything * with EDID on it */ status = connector_status_disconnected; goto out; } /* * Some external monitors do not signal loss of link synchronization * with an IRQ_HPD, so force a link status check. */ if (!intel_dp_is_edp(intel_dp)) { ret = intel_dp_retrain_link(encoder, ctx); if (ret) return ret; }