On Qualcomm X1E80100 / X1P42100 platforms using the Parade PS883x retimer, hotplugging USB4-capable docks such as the Lenovo 40B0 can result in working USB but no DisplayPort output. When the dock negotiates USB4, the retimer receives TYPEC_MODE_USB4 and forwards it via typec_mux_set(). The qmp-combo PHY then selects USB3-only because no classic DP altmode SVID is present in the state, leaving the DP transmitter and AUX channel disabled. Reject USB4 with -EOPNOTSUPP on platforms whose USB4 / DP-tunneling stack is not ready yet. The Type-C stack then falls back to USB3 + DP Alt Mode. DP altmode configuration continues to use the existing ps883x_set() path. Use a machine-compatible table rather than a DT property so the quirk stays inside the kernel and can be removed later without creating ABI. Assisted-by: Grok(xAI):4.6 Tested-by: Dr. David Alan Gilbert <dave@treblig.org> Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Jens Glathe <jens.glathe@oldschoolsolutions.biz> Link: https://patch.msgid.link/20260922-ps883x-disable-usb4-v5-3-02c0414978e6@oldschoolsolutions.biz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>