dcaf6123

By: Ammar <ammar.nanjiani@gmail.com>

fix(steammachine): keep the Bluetooth radio out of USB autosuspend

An external controller (Switch Pro Controller) dropped and re-paired every
few minutes. The kernel log showed the link being torn down mid-traffic:

  Bluetooth: hci0: ACL packet for unknown connection handle 2
  nintendo 0005:057E:2009.00XX: joycon_enforce_subcmd_rate: exceeded max attempts

Cause: the Bluetooth radio is an integrated Valve USB device (28de:1401)
and btusb enables USB autosuspend by default. The adapter really does
sleep — one boot showed runtime_suspended_time 3,238,298 ms against
runtime_active_time 4,053,263 ms. Waking it drops the radio link.

The Steam Controller's own puck arrives with power/control already set to
"on", which is why that controller was never affected. No udev rule sets
that, so the protection is incidental; pin the Bluetooth radio explicitly
rather than depend on the same accident.

Verified at runtime before making it declarative: writing "on" to
/sys/bus/usb/devices/1-5/power/control stopped the drops.

Scoped to idProduct 1401 so it cannot affect the Steam Controller puck or
any other Valve device.

Total

1m37s

Timeline