Steam Deck pass-through (design/steam-deck-passthrough-plan.md), code-complete +
all CI checks green on Linux + adversarially reviewed; on-glass validation pending:
- usbip/`vhci_hcd` virtual Deck transport (inject/linux/steam_usbip.rs) for
non-SteamOS hosts (Bazzite/generic) — presents a real interface-2 USB Deck so
Steam Input promotes it. In-process vhci attach (loopback OP_REQ_IMPORT handshake
→ sysfs attach) with a bounded `usbip`-CLI fallback; detach on drop.
- Backed by a vendored, libusb-free trim of the `usbip` crate
(crates/punktfunk-host/vendor/usbip-sim, MIT + NOTICE; host/cdc/hid + rusb/nusb
removed; interrupt-IN paced by bInterval).
- Selection ladder raw_gadget (SteamOS fast-path) → usbip (universal) → UHID,
with PUNKTFUNK_STEAM_USBIP / PUNKTFUNK_USBIP_ATTACH knobs.
- Shared Deck descriptors + the 0x83/0xAE feature contract + a Steam-accepted
serial consolidated into steam_proto.rs; the raw_gadget backend reuses them.
- Linux client leave-shortcuts: Ctrl+Alt+Shift+D + holding the escape chord
(L1+R1+Start+Select) >=1.5s end the session (short press still exits
fullscreen); the chord state resets across sessions.
Also bundles in-progress work already staged in the tree:
- host(kwin): xdg-output logical-geometry mapping so the KWin fake_input backend
places absolute coordinates correctly under display scaling.
- docs: design/README index entries + design/controller-only-mode.md.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
enricobuehler
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