The in-kernel rtw89_8852bu on this Ubuntu kernel base predates mainline's
USB2->3 auto-switch for this chip, permanently capping the AP dongle at
USB2/480M. morrownr/rtw89 (dkms) has that switch. ap/rtw89.conf now
blacklists the in-kernel rtw89 modules and tunes the replacement
(disable_ps_mode + switch_usb_mode); ap/install-rtw89-driver.sh builds
and installs it, pinned to a specific upstream commit, kept separate
from deploy.sh since a dkms rebuild is too slow to run on every deploy.
Verified live: negotiates USB3/5000M on a dedicated USB3 controller
(480M on a USB2-only one, as expected), AP recovered via hostapd's
Restart=always + van-ap-watchdog with no manual intervention. Hit and
documented one real gotcha along the way: in-kernel rtw89_core refused
to unload while its own dependents (rtw89_8852b, rtw89_8852b_common)
were still loaded, which blocked the new module with a duplicate-symbol
error until all in-kernel modules were removed first.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YJfEELeh3ercpRBp8yYrYS
Andreas WredeandClaude Sonnet 5