forked from unom/punktfunk
enricobuehler
77f0a25d18
The field report that started this work was an Xbox controller that no game could see on a Windows host for two weeks. Root cause was that our Xbox pad reaches no Windows input API a modern title uses. This is the fix, and it is two registry values. Windows promotes Xbox pads with `xinputhid`, whose INF is an explicit hardware-id ALLOW-LIST — its own comment says "we can not use a Compatability ID for the loading of this driver, and so rely on individual hardware IDs". A software-enumerated devnode can never match those ids, so we write what the matching install sections would have written. `045E:0B13`, the PID this identity already claimed, is on that allow-list twice, so the identity choice turned out to be exactly right. 🛑 THE PAIRING IS THE WHOLE FINDING, AND THE TWO VALUES GO IN DIFFERENT KEYS. `UpperFilters` is a `.HW` AddReg (hardware key); `DevicePropertyFlags` is a DDInstall AddReg (software key). A live A/B on .173: removing `DevicePropertyFlags` alone reverts EVERYTHING — no `IG_00`, no XUSB interface, no XInput, no WGI entry — while `UpperFilters` alone is completely inert. `1` = `BusDevice`, which Microsoft glosses as "a focused bus filter driver for the IG_ problem". It is not a description of the device, it is the switch. An earlier session installed the filter WITHOUT it, measured a device that produced nothing, and recorded "never ship it". The filter was never broken; it had never been switched on. That conclusion is now retracted. ⚠️ The Xbox line gets its OWN DDInstall section, `pfGamepadXbox`. All five identities previously shared `pfGamepad`, so an AddReg there would have handed a DualSense, DualShock 4, Edge and Steam Deck to Microsoft's Xbox translator. The regression check below exists for exactly that. MEASURED ON .173 (Win11 26200), INF-SHIPPED — no hand-written registry values: * `UpperFilters=xinputhid` lands on the hardware key and `DevicePropertyFlags=1` on the software key, applied by the INF at install. * The HID child gains the `IG_00` token: `HID\PUNKTFUNK&IG_00\...`. * An XUSB interface appears: `\\?\hid#punktfunk&ig_00#...#{ec87f1e3-...}`. * classic XInput reads it live — packets ADVANCING, `buttons=0x1000` (the devtest's A), and the stick sweeping. XInput had NEVER seen this backend before. * `XInputSetState` rumble round-trips: `rumble from game: pad=0 low=65535 high=32767`. * REGRESSION CHECK PASSED: with the DualSense identity up, its devnode has an EMPTY `UpperFilters` and no `DevicePropertyFlags`. The PlayStation pads are untouched. WGI `Gamepad` lists the pad but reads `ts=0`. That is NOT ours: a real Xbox Elite Series 2, promoted by Microsoft's own driver on the same box, reads `ts=0` in WGI at the very moment classic XInput is reading live data from it (`buttons=0x1000 LY=-32768`). Our pad is behaviourally indistinguishable from real hardware here; the row is a property of the non-interactive session. NOT VERIFIED * On-glass in a console session. Everything above ran over ssh, which is what makes the WGI row unreadable; the real-Elite control is what settles it, not a clean WGI reading. * GameInput — no binding in the `windows` crate, still unmeasured for this backend. * `PUNKTFUNK_XBOX_BACKEND` still defaults to XUSB. This changes what the HID backend CAN do; it does not change which backend is chosen. That is WP-E and it is a separate decision. * Trigger-actuator enable bits, still conjecture — `XINPUT_VIBRATION` has two members and cannot exercise them.