Nested games on the Bazzite host saw the wrong display: refresh capped at 60 Hz,
the box's connected TV's EDID modes leaking in (DOOM landed on 2560×1440@60), and
the resolution fixed at whatever the always-on session was launched at — the
client's requested mode never reached the game. Root causes: the session-plus
gamescope command has no --nested-refresh (Xwayland advertises 59.96 Hz for every
mode), --prefer-output HDMI-A-1 makes gamescope read the TV EDID, and the ATTACH
model launches one fixed-resolution session.
New vdisplay path: PUNKTFUNK_GAMESCOPE_SESSION=<client> — the host LAUNCHES
gamescope-session-plus headless AT THE CLIENT'S mode and relaunches it when the
mode changes. Injected via a host-written GAMESCOPE_BIN wrapper (--nested-refresh
$PF_HZ, the flag session-plus doesn't expose) + DRM_MODE=cvt (gamescope generates
clean CVT modes at that refresh instead of the TV's EDID). The session runs as a
transient `systemd-run --user` unit (clean cgroup teardown of the Steam tree);
state lives in a host-lifetime static (MANAGED_SESSION), NOT in GamescopeDisplay
(which is per-client-session) — so a same-mode reconnect REUSES the running
session instantly (no Steam restart) while a different mode RELAUNCHES it (games
can't change output mode live; a game/Steam restart on a mode change is
unavoidable and acceptable). Reuses the existing node + EIS auto-discovery
(find_gamescope_node / find_gamescope_eis_socket, factored into
point_injector_at_eis) and the existing mid-stream Reconfigure → vd.create(mode)
machinery — no protocol or m3 control-flow change.
Validated live on bazzite (RTX 4090): games' Xwayland now advertises 5120×1440 @
239.90 Hz as the preferred mode (was 59.96), the TV's 3840×2160/4096×2160@60 modes
are gone, frames stream; reconnect at 1920×1080@120 relaunches and games see that;
same-mode reconnect reuses with no restart and frames flow instantly.
scripts: host.env.example documents PUNKTFUNK_GAMESCOPE_SESSION (mutually exclusive
with the legacy NODE=auto attach); punktfunk-steam-session.service marked
deprecated (superseded — must not run alongside the host-managed path).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
The host warns when its UDP socket-buffer grant is small (Linux caps SO_SNDBUF at
net.core.wmem_max, ~208 KB by default). Validated zero-loss at 5K even at that cap,
but raising it gives send-side headroom for higher bitrates / concurrent sessions.
Referenced from the headless-Steam appliance setup. macOS clients need no tuning.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Bazzite (and SteamOS-like hosts) run Steam Big Picture inside their OWN
gamescope-session-plus session. Nesting a second gamescope+Steam can't work — the
second Steam sees the first and exits, taking the nested gamescope down with it
(crash in its exit handlers), killing both video and input. The robust model is to
let punktfunk OWN that session: run gamescope-session-plus headless at the client's
resolution (full Steam Deck UI polish: MangoApp, VRR, controller config) and have
the host ATTACH to it rather than spawn its own.
The video half already existed (PUNKTFUNK_GAMESCOPE_NODE=<id> attaches to a
PipeWire node). This finishes it:
- PUNKTFUNK_GAMESCOPE_NODE=auto discovers the gamescope Video/Source node, so the
(dynamic) node id needn't be hand-wired.
- The attach path now also points the libei injector at the running session's EIS
socket: find_gamescope_eis_socket() scans XDG_RUNTIME_DIR for gamescope-<N>-ei,
connect()-probes each (stale dead-session sockets refuse), and writes the newest
live one to the relay file the injector reads. So input reaches the attached
session with zero manual config.
scripts/punktfunk-steam-session.service: a systemd --user unit that runs
gamescope-session-plus headless at a configured resolution, with the one-time
headless-appliance setup (linger + multi-user.target) documented inline.
Validated live on bazzite (RTX 4090): the full Steam Big Picture session streams
(1499 frames, p50 ~1ms) with mouse/keyboard injected into it (device resumed, all
caps, emitted=true), node + EIS socket both auto-detected.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
enricobuehler