enricobuehler
ce5047f3ad
G6 + G15 of the gyro program. G6 — the UMDF gamepad driver's input path. Its timer ran at 8 ms and completed one pended READ_REPORT per tick, so a game could observe at most ~125 Hz while clients stream motion at ~250 Hz: every other sample was overwritten in the slot before anything read it, and the ones that survived carried up to 8 ms of extra latency. For gyro, a dropped sample is not a dropped frame — it is rotation that never reaches the game. The timer now ticks at 2 ms (about a real DualShock 4's Bluetooth cadence). Only the cheap half runs on every tick: read the input slot, complete one pended read. The channel handshake and the health marks stay on their historical ~8 ms, because they cost more, nothing wants them faster, and `driver_heartbeat`'s documented "+1 per ~8 ms tick" is what the host reads as liveness. The same slot is a single unqueued buffer that both sides touch without a lock, so a driver read landing mid-copy handed the game a report that was half the previous frame and half the next. For a button that is a one-tick glitch; for motion it is a spike in angular velocity, which an integrator turns into aim movement. `PadShm` gains an `input_gen` seqlock (v2.3, carved from reserved space inside the v2 legacy region): the host takes it odd, fences, writes the 64 bytes, and stores it even; the driver samples it either side of its read and retries once. The old code's own comment called this out as a known residual — it is now closed rather than documented. Version posture matches the ring's, with one simplification: no capability stamp is needed, because an old host never writes the field and a constant 0 is indistinguishable from "no write in flight", so a new driver against an old host behaves exactly as it does today, and an old driver ignores the field entirely. The Steam Deck write path had neither the seqlock nor even the trailing Release its DualSense sibling carried; all three Windows backends now publish through one `publish_input`. G15 — motion-cadence observability. The host already computed the measurement a "gyro feels floaty" report needs (client inter-arrival percentiles), but kept ONE global accumulator, so two motion-capable pads in a session interleaved into each other's gaps and produced a number describing neither. It also sat at `debug` behind a `tracing::enabled!` check, so a field log arrived with nothing in it and the only way to get the measurement was to ask for a re-run. Now per-pad and always on, summarized at `info` when the session ends — the moment a field report is being written. It costs one subtraction and one array increment per sample: percentiles come from a fixed log2 histogram instead of a growing sorted Vec, so there is no allocation, no per-window sort, and no way for a client streaming as fast as the link allows to make the instrument expensive. Percentiles are reported as bucket upper bounds (`_le`), which is a factor-of-two answer to a question whose answers are orders of magnitude apart. Gaps of 500 ms or more are counted as stalls rather than folded into the percentiles — an interruption is not a cadence, and averaging it in would report a healthy feed as a terrible one. Gates. Windows CI runner .133, the drivers workspace on the real WDK: cargo build, clippy -D warnings (which enforces the unsafe-audit lints), and fmt — all green, against a source whose SHA-256 matches this commit's. Linux CI image: fmt, build, clippy --all-targets -D warnings over pf-inject / punktfunk-core / punktfunk-probe / pf-client-core / pf-driver-proto / punktfunk-host, and the test suites including the 5 new motion-cadence tests — all green. Not measured on glass. G6's stated gate is a sensor-rate reading (SDL testcontroller or Steam's calibration screen) that matches the client's send rate; that is still owed, and a driver change only a compile has seen deserves it before anyone trusts the number.
Packaging punktfunk for Fedora / Bazzite
The punktfunk host links system FFmpeg (NVENC on NVIDIA, VAAPI on AMD/Intel, with a GPU-less software-H.264 fallback), PipeWire and Opus. This page covers packaging it for the Fedora Atomic / Bazzite world (rpm-ostree + bootc), where most of those deps are already present; the NVIDIA-specific notes below apply to the NVENC path.
👉 Ubuntu/Debian hosts install via
aptfrom Gitea's package registry — seedebian/README.md(apt update && apt upgradefor new builds).
👉 End-to-end Bazzite setup walkthrough (install → udev/group →
host.env→ service → firewall → verify → troubleshooting):bazzite/README.md. This file is the higher-level packaging rationale.
packaging/
rpm/punktfunk.spec # the RPM (builds punktfunk-host from source with cargo)
bazzite/host.env # gamescope-default config for a Bazzite appliance
bazzite/README.md # step-by-step Bazzite setup guide
bazzite/*sysext*.sh # the no-layering path: build/install/publish the systemd-sysext
bootc/Containerfile # bake punktfunk into a Bazzite-based atomic image
copr/ # COPR build-from-SCM settings
The other packaging targets have their own READMEs: debian/ (apt),
arch/ (pacman binary repo + PKGBUILD + SteamOS sysext),
flatpak/ (the client), windows/ (host installer +
drivers), plus kde/ and linux/ helpers. NixOS / Nix users get a flake (flake.nix at the
repo root) with reproducible host + client packages and a services.punktfunk NixOS module —
see nix/README.md.
What's needed beyond base Fedora
| Dependency | Where it comes from |
|---|---|
ffmpeg-libs with NVENC |
RPM Fusion nonfree (ffmpeg, not ffmpeg-free) |
NVIDIA driver (libnvidia-encode, libEGL_nvidia) |
Bazzite -nvidia images ship it; plain Fedora: akmod-nvidia + xorg-x11-drv-nvidia-cuda |
| gamescope, PipeWire, wireplumber | Bazzite ships these; plain Fedora: dnf install gamescope pipewire wireplumber |
opus, libei |
Fedora base / updates |
On Bazzite the only genuinely new runtime bits are ffmpeg-libs (RPM Fusion) + opus +
libei — the rest of the stack is already there. The default backend is gamescope
(packaging/bazzite/host.env), which the host spawns headless per session — no desktop login.
Option A — systemd-sysext (recommended; no layering, no reboot)
On Bazzite / Fedora Atomic the recommended install is the systemd-sysext image — rpm-ostree
layering is a last resort per the Bazzite docs (it slows every OS update and can block upgrades),
while a sysext overlays /usr at runtime, survives OS updates, and updates in one command with
no reboot. CI wraps the same RPMs below into the image, so content and channels are identical.
curl -fsSLO https://git.unom.io/unom/punktfunk/raw/branch/main/packaging/bazzite/punktfunk-sysext.sh
sudo bash punktfunk-sysext.sh install # then: sudo punktfunk-sysext update | status | remove
Full walkthrough (incl. the F43→F44 rebase behavior and migration off layering):
bazzite/README.md.
Option B — Gitea RPM registry (per-host, rpm-ostree layering)
The host's RPM is published to unom's self-hosted Gitea RPM registry (CI builds it on every
push), mirroring the Debian/apt setup. Add one repo file, install, and track
updates with rpm-ostree upgrade — no COPR account needed. Full guide: rpm/README.md.
# GPG-signed pkgs + Gitea-signed metadata → gpgcheck=1, repo_gpgcheck=1 (see rpm/README.md)
sudo tee /etc/yum.repos.d/punktfunk.repo >/dev/null <<'REPO'
[gitea-unom-bazzite]
name=punktfunk (unom, Bazzite)
baseurl=https://git.unom.io/api/packages/unom/rpm/bazzite
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://git.unom.io/api/packages/unom/rpm/repository.key
https://git.unom.io/api/packages/unom/generic/punktfunk-keys/1/RPM-GPG-KEY-punktfunk
REPO
rpm-ostree install punktfunk && systemctl reboot
# updates: rpm-ostree upgrade && systemctl reboot
Option C — COPR (per-host, rpm-ostree install)
- Create a COPR project, enable build-from-SCM pointing at this repo, spec path
packaging/rpm/punktfunk.spec(seecopr/README.md). Under External Repositories add RPM Fusion nonfree soffmpeg-develresolves at build time. - On the Bazzite host:
# RPM Fusion (for the NVENC ffmpeg) — usually already enabled on Bazzite rpm-ostree install \ https://mirrors.rpmfusion.org/free/fedora/rpmfusion-free-release-$(rpm -E %fedora).noarch.rpm \ https://mirrors.rpmfusion.org/nonfree/fedora/rpmfusion-nonfree-release-$(rpm -E %fedora).noarch.rpm # enable the COPR + install punktfunk sudo wget -O /etc/yum.repos.d/_copr_punktfunk.repo \ https://copr.fedorainfracloud.org/coprs/enricobuehler/punktfunk/repo/fedora-$(rpm -E %fedora)/ rpm-ostree install punktfunk systemctl reboot
Option D — bootc (image-based, atomic)
Layer punktfunk into a Bazzite image once, then rebase any number of hosts onto it — no
per-host drift. See bootc/Containerfile:
podman build -t ghcr.io/<you>/bazzite-punktfunk -f packaging/bootc/Containerfile .
podman push ghcr.io/<you>/bazzite-punktfunk
# on the target:
sudo bootc switch ghcr.io/<you>/bazzite-punktfunk && systemctl reboot
First-run setup (all options)
ujust add-user-to-input-group # virtual gamepads need /dev/uinput (then re-login).
# On Bazzite use ujust, NOT `usermod -aG input` (atomic OS — it won't stick).
mkdir -p ~/.config/punktfunk
cp /usr/share/punktfunk/host.env.bazzite ~/.config/punktfunk/host.env # edit (gamescope app, etc.)
systemctl --user enable --now punktfunk-host
# Management web console (pairing + status) — pulled in by default (the host RPM Recommends it;
# `--no-install-recommends` / headless-only boxes can skip it). Enable it and read the login password:
systemctl --user enable --now punktfunk-web
journalctl --user -u punktfunk-web-init | sed -n 's/.*password generated: //p' # then open https://<host-ip>:47992
Pair a stock Moonlight client (mDNS-discovered), or connect the native punktfunk/1 client — via the
web console at https://<host-ip>:47992 or directly.
⚠️ COPR caveat: COPR's mock chroot has no
bun, so a COPR build produces onlypunktfunk+punktfunk-client— notpunktfunk-web. For the console on a COPR/bootc host, install from the Gitea RPM registry (Option B — it carriespunktfunk-web; the sysext image includes it too), which is also whybootc/Containerfileinstalls from there rather than COPR.
Why not Flatpak (for the HOST)?
The host needs unsandboxed access the zero-copy NVENC path, /dev/uinput, the PipeWire
graph and the compositor's privileged protocols — a Flatpak sandbox fights all of these.
An RPM (or the bootc layer) installs into the host system where those just work.
👉 The client is a different story — it IS shipped as a Flatpak (the only viable Steam Deck install path: SteamOS
/usris read-only and lackslibadwaita/libSDL3). Seeflatpak/README.md. The client sandbox only needs the GPU render node, Wayland, PipeWire audio, the network and hidraw — all expressible as finish-args.
Building the SRPM/RPM locally (Fedora only)
git archive --format=tar.gz --prefix=punktfunk-0.3.0/ -o ~/rpmbuild/SOURCES/punktfunk-0.3.0.tar.gz HEAD
rpmbuild -ba packaging/rpm/punktfunk.spec # needs the BuildRequires from the spec
# (0.3.0 = the spec's default %{pf_version}; the prefix and tarball name must match it)
(Not buildable on Debian/Ubuntu — use a Fedora toolbox/container or COPR.)