The virtual Steam Deck pad only appears in the host's Game Mode (and is
navigable) when it arrives as a real USB device via the usbip/vhci_hcd
transport — Steam Input won't promote the UHID hid-steam fallback
(Interface: -1). The host runs as an unprivileged --user service, so it
cannot modprobe vhci_hcd itself; the module must be loaded at boot and the
vhci attach/detach sysfs files chgrp'd to the `input` group by the udev
rule.
Packaging ships modules-load.d/punktfunk.conf + 60-punktfunk.rules under
the sysext's /usr/lib, but a systemd-sysext image MERGES after
systemd-modules-load and early udev have already run, so on a plain reboot
of a sysext host (e.g. Bazzite) those files are read too late: vhci_hcd is
never loaded, usbip fails, and the pad silently degrades to non-promoted
UHID — the controller vanishes from Game Mode. (deb/arch/rpm are
unaffected: real /usr is present at early boot.)
Fix: sysext post_merge now mirrors BOTH files into real /etc (read at the
normal early-boot time, shadowing the /usr copies by filename; refreshed
every merge since neither is user config), then reloads udev, modprobes
vhci-hcd, and re-triggers the vhci platform device for the live session.
Also raise the UHID-fallback log INFO->WARN with an actionable hint.
Verified on the .41 sysext host: after the /etc mirror, unloading vhci_hcd
and restarting systemd-modules-load (the real reader of /etc/modules-load.d)
reloads the module; a udev coldplug trigger makes attach/detach root:input
0660; the unprivileged host user can then write attach — the exact working
precondition for the usbip transport, now durable across reboot.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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>
Layering is a last resort per the Bazzite docs (slows every OS update, can
block upgrades until removed); a sysext never enters an rpm-ostree
transaction, survives OS updates, and installs/updates with no reboot —
the mechanism Fedora Atomic ships via fedora-sysexts.
- build-sysext.sh wraps the built host+web RPMs into punktfunk-<V-R>-x86-64.raw:
/etc payload relocated to /usr/share/punktfunk/etc (a sysext carries only
/usr), the punktfunk-sysext helper embedded, ID=fedora + VERSION_ID pinned
(merges on Bazzite via ID_LIKE; REFUSED after a major rebase instead of
running soname-broken binaries — both behaviors validated live on Bazzite 43).
SELinux labels are baked in as squashfs pseudo-xattrs from matchpathcon:
unlabeled files run fine for user units but system daemons are DENIED
(udev couldn't read the gamepad rule under enforcing) — validated on-glass.
Refuses duplicate input package names (a stale noarch punktfunk-web next to
the x86_64 one built a chimera image with the dead node launcher once).
- punktfunk-sysext.sh: install/update/status/remove against per-Fedora-major
feeds (…/generic/punktfunk-sysext/f43[-canary]), SHA-256-verified, applies
the udev/sysctl scriptlet work + /etc copies, prints the layering-migration
hint. Live-validated on the .41 Bazzite box incl. service restart + web console.
- publish-sysext-feed.sh + rpm.yml: build + publish the image per matrix leg
(fedver 43/44), canary feeds pruned to 6, stable release assets attached.
- update-punktfunk.sh warns when the sysext shadows a layered install.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
enricobuehlerandClaude Opus 4.8