#!/usr/bin/env bash
# ap/install-rtw89-driver.sh — install/update the out-of-tree morrownr/rtw89 driver
# for the 5GHz AP dongle (RTL8852BU, USB).
#
# Why: this Ubuntu kernel base predates mainline rtw89's USB2->3 auto-switch for this
# chip, so the in-kernel rtw89_8852bu permanently caps the dongle at USB2/480M. The
# morrownr/rtw89 driver has that switch. ap/rtw89.conf blacklists the in-kernel rtw89
# modules so udev loads this one instead — that file is deploy.sh's job to install;
# this script is the (heavier, slower, not idempotent-per-deploy) driver build/install
# itself, kept separate so a routine `deploy.sh` run doesn't trigger a dkms rebuild.
#
# Run manually after a fresh Pi provisioning, or to bump PIN_COMMIT to a newer upstream
# revision: sudo ./ap/install-rtw89-driver.sh
#
# Safe to re-run — no-ops if the pinned commit is already built+installed for the
# running kernel (e.g. after a kernel upgrade where DKMS's own auto-rebuild already
# handled it).
set -euo pipefail

[ "$(id -u)" -eq 0 ] || { echo "Run as root (sudo)." >&2; exit 1; }

REPO_URL=https://github.com/morrownr/rtw89
# Pinned for reproducibility — bump deliberately, not by tracking a moving branch.
PIN_COMMIT=8b2b78deb357d01fd5808164046e31239139ed9f
PKG_NAME=rtw89
PKG_VERSION=7.3   # from upstream's dkms.conf; independent of PIN_COMMIT
SRC="/usr/src/${PKG_NAME}-${PKG_VERSION}"
KVER=$(uname -r)

if [ -d "$SRC/.git" ]; then
    git -C "$SRC" fetch origin
else
    rm -rf "$SRC"
    git clone "$REPO_URL" "$SRC"
fi
git -C "$SRC" checkout "$PIN_COMMIT"

if dkms status "${PKG_NAME}/${PKG_VERSION}" 2>/dev/null | grep -q "${KVER}.*: installed" \
   && [ "$(git -C "$SRC" rev-parse HEAD)" = "$PIN_COMMIT" ]; then
    echo "rtw89 driver already installed at pinned commit ${PIN_COMMIT:0:12} for ${KVER}; nothing to do."
    exit 0
fi

dkms remove "${PKG_NAME}/${PKG_VERSION}" --all 2>/dev/null || true
dkms add "$SRC"
dkms install "${PKG_NAME}/${PKG_VERSION}"
make -C "$SRC" install_fw

cat <<EOF

rtw89 driver installed (commit ${PIN_COMMIT:0:12}) for kernel ${KVER}.

If in-kernel rtw89 modules are currently loaded, they won't unload themselves —
loading this driver alongside them fails with "exports duplicate symbol" (hit this
2026-08-23: rtw89_core stayed resident because rtw89_8852b/rtw89_8852b_common, its own
in-kernel dependents, were still loaded too). To switch a live system over:

  sudo rmmod rtw89_8852bu rtw89_8852b rtw89_8852b_common rtw89_core rtw89_usb 2>/dev/null
  # then force the AP dongle to re-enumerate, e.g.:
  echo 0 | sudo tee /sys/bus/usb/devices/<bus-port>/authorized
  echo 1 | sudo tee /sys/bus/usb/devices/<bus-port>/authorized

(or just reboot). hostapd's Restart=always + van-ap-watchdog recover the AP
automatically once the new driver claims the interface — no manual hostapd restart
needed. ap/rtw89.conf must already be deployed (sudo ./deploy.sh) so the blacklist is
in place before the device re-enumerates, or the in-kernel driver will just reclaim it.
EOF