On PoE sites the MIPI-DSI panel can lose its init on a supply dip while the
RK3566 keeps running; the UI may also hang or exit. Three layers:
- hardware watchdog: systemd RuntimeWatchdogSec=20s (system.conf.d)
- GUI: SdWatchdog pings systemd per swapped frame (WATCHDOG_USEC=30s, enabled
by the binary so older versions run under the same unit) and writes
run/qt.frame; buttontask.service gets Restart=always, NotifyAccess=main,
TimeoutAbortSec=10s
- bt-displaywatch (root, buttontask-displaywatch.service): kernel DRM/DSI
timeouts, eth link down->up (PoE dip hint), stale UI frames, restart storms
-> panel re-init (stop UI, fb0 blank 4->0, start UI), repeated -> reboot
(max 3/day, never during OTA); incident log in /var/log/buttontask/
Manual recovery: hold one finger 10 s in the bottom-left corner (panels are
single-touch). Delivered by OTA via bt-update sync_system; the web service
runs `bt-update sync-system` at start for devices updated by an older
bt-update.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
- every BlueZ call runs off the asyncio thread with a timeout; if bluetoothd
stays unresponsive for 30 s the collector restarts bluetooth.service and
exits for a clean re-registration
- Type=notify + WatchdogSec for buttontask-collector, never give up restarting
- bluetooth.service drop-in: Restart=always (BlueZ 5.55 crashes on assert/SEGV),
installed by device-install.sh and OTA (bt-update)
- bt-service: bluez-restart action for the collector
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
GrigoandClaude Opus 5.5