Steam Input only adopts the virtual Steam Deck controller when it arrives as
a real USB device (raw_gadget or usbip/vhci transports); the UHID fallback
has no USB interface and Steam ignores it. On a stock host neither
precondition for usbip held: vhci-hcd isn't loaded, and its sysfs
attach/detach files are root-only while the host runs as a user service —
so every session silently fell back to UHID and 'no controller appears on
the host' (live-debugged 2026-07-08: client events all arrived, the pad
existed, Steam just refused it).
Ship both preconditions with the host packages:
* modules-load.d/punktfunk.conf loads vhci-hcd at boot (rpm/deb/arch;
Bazzite gets it via the RPM payload + a modprobe in the sysext
post-merge hook)
* a udev rule in 60-punktfunk.rules grants the input group write on
vhci_hcd's attach/detach whenever the device appears
Verified end-to-end on a live host: usbip in-process attach, hid-steam
binds all three interfaces, 'Steam Deck' + motion evdev appear, and Steam
adopts the pad (client-mode grab + its own virtual X360 emission).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>