Steam validates the Deck unit serial's format before accepting it. Our
"PFDK..." serial was REJECTED ("Invalid or missing unit serial number"), so
Steam substituted a hash identity and mangled the displayed name to
"Steam Deck Controllerggg" on every host tested. An 'F'-leading serial passes,
so switch to "FVPF..." — keeps the PunktFunk marker one slot in, still distinct
from a real Deck's "FVZZ..." for the Linux self-detection in
physical_steam_controller_present(). The name now shows a clean "Steam Deck
Controller" with a serial-derived handle (verified on .173).
Also fix the UMDF driver's 0xAE GET_STRING_ATTRIBUTE handler to echo the
requested attribute id faithfully instead of collapsing board-serial (0x00)
requests to unit-serial (0x01). Steam still logs a benign "Deck Controller PCB
Serial# invalid" for the board serial — it validates that against a
Valve-internal format for ANY value, including an empty one (verified) — but
that line does not mangle the name, change the handle, or block promotion.
Applied to both transports: host inject/proto/steam_proto.rs::deck_serial
(Linux gadget/usbip) and the pf-dualsense UMDF driver (Windows), which mirror
each other's serial format.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
enricobuehler
f3b6ccaa7f