Verify YT6801 cutover before retiring the vendor driver

migrations/1788279117.sh

@@ -1,43 +1,86 @@
 echo "Replace the YT6801 vendor DKMS driver with the upstream kernel driver"
 
-mapfile -t yt6801_devices < <(lspci -Dn -d 1f0a:6801 | awk '{ print $1 }')
-
-if (( ${#yt6801_devices[@]} == 0 )); then
-  omarchy-pkg-drop yt6801-dkms
-  exit 0
-fi
-
-for device in "${yt6801_devices[@]}"; do
-  if [[ ! $device =~ ^[[:xdigit:]]{4}:[[:xdigit:]]{2}:[[:xdigit:]]{2}\.[[:xdigit:]]$ ]]; then
-    echo "Invalid YT6801 PCI address: $device" >&2
-    exit 1
-  fi
-done
-
-if ! modinfo -F alias dwmac-motorcomm | grep -Fqx 'pci:v00001F0Ad00006801sv*sd*bc*sc*i*'; then
-  echo "The running kernel does not provide YT6801 support in dwmac-motorcomm." >&2
-  echo "Reboot into the latest Omarchy kernel and rerun omarchy-migrate." >&2
+if ! yt6801_pci=$(lspci -Dn -d 1f0a:6801); then
+  echo "Unable to discover YT6801 adapters; rerun omarchy-migrate." >&2
   exit 1
 fi
 
-# Load and validate the replacement before removing the installed fallback.
-sudo modprobe dwmac-motorcomm
-omarchy-pkg-drop yt6801-dkms
+yt6801_devices=()
+while read -r device _; do
+  [[ -n $device ]] || continue
+  if [[ ! $device =~ ^[[:xdigit:]]{4}:[[:xdigit:]]{2}:[[:xdigit:]]{2}\.[0-7]$ ]]; then
+    echo "Invalid YT6801 PCI address: $device" >&2
+    exit 1
+  fi
+  yt6801_devices+=("$device")
+done <<< "$yt6801_pci"
 
-if lsmod | awk '$1 == "yt6801" { found = 1 } END { exit !found }'; then
-  sudo modprobe -r yt6801
+yt6801_uses_upstream() {
+  local driver
+  driver=$(readlink -f "/sys/bus/pci/devices/$1/driver") &&
+    [[ $driver == "/sys/bus/pci/drivers/dwmac-motorcomm" ]]
+}
+
+yt6801_check_binding() {
+  local device
+  for device in "${yt6801_devices[@]}"; do
+    if ! yt6801_uses_upstream "$device"; then
+      echo "YT6801 device $device did not bind to dwmac-motorcomm." >&2
+      echo "Reboot into the latest Omarchy kernel and rerun omarchy-migrate." >&2
+      exit 1
+    fi
+  done
+}
+
+# Check discovery before changing hardware or packages. A failed query must not
+# turn into an empty list and mark the migration complete.
+installed_packages=$(pacman -Qq)
+loaded_modules=$(lsmod)
+
+yt6801_pending=()
+for device in "${yt6801_devices[@]}"; do
+  if ! yt6801_uses_upstream "$device"; then
+    yt6801_pending+=("$device")
+  fi
+done
+
+if (( ${#yt6801_pending[@]} > 0 )); then
+  if ! aliases=$(modinfo -F alias dwmac-motorcomm) ||
+    ! grep -Fxq 'pci:v00001F0Ad00006801sv*sd*bc*sc*i*' <<< "$aliases"; then
+    echo "The running kernel does not provide YT6801 support in dwmac-motorcomm." >&2
+    echo "Reboot into the latest Omarchy kernel and rerun omarchy-migrate." >&2
+    exit 1
+  fi
+
+  # Validate the replacement before unloading the installed fallback. Already
+  # migrated machines need no module load or privilege prompt for later users.
+  sudo modprobe dwmac-motorcomm
 fi
 
-for device in "${yt6801_devices[@]}"; do
-  if ! lspci -Dks "$device" | grep -Eq 'Kernel driver in use: dwmac[-_]motorcomm'; then
+if grep -Eq '^yt6801[[:space:]]' <<< "$loaded_modules"; then
+  # rmmod also works on retries after DKMS has deleted the module files and
+  # lookup index. Never force removal of a module that is still busy.
+  sudo rmmod yt6801
+fi
+
+for device in "${yt6801_pending[@]}"; do
+  if ! yt6801_uses_upstream "$device"; then
     printf '%s\n' "$device" | sudo tee /sys/bus/pci/drivers_probe >/dev/null
   fi
 done
+yt6801_check_binding
 
-for device in "${yt6801_devices[@]}"; do
-  if ! lspci -Dks "$device" | grep -Eq 'Kernel driver in use: dwmac[-_]motorcomm'; then
-    echo "YT6801 device $device did not bind to dwmac-motorcomm." >&2
-    echo "Reboot and rerun omarchy-migrate." >&2
-    exit 1
-  fi
-done
+# Keep the package available until the live cutover succeeds. Package removal
+# invokes DKMS/depmod hooks, so unloading must happen before this transaction.
+if grep -Fxq 'yt6801-dkms' <<< "$installed_packages"; then
+  omarchy-pkg-drop yt6801-dkms
+fi
+
+installed_packages=$(pacman -Qq)
+loaded_modules=$(lsmod)
+if grep -Fxq 'yt6801-dkms' <<< "$installed_packages" ||
+  grep -Eq '^yt6801[[:space:]]' <<< "$loaded_modules"; then
+  echo "The YT6801 vendor package or module is still present; rerun omarchy-migrate." >&2
+  exit 1
+fi
+yt6801_check_binding