+Close media players and file managers, and unmount any filesystem from the
+selected drive. Linux currently provides no FriiDump-exclusive optical-volume
+lock equivalent for this path.
+
+For the validated cross-flashed GDR-8050L USB path, do not use standalone
+`sg_turs`, `sg_prevent`, or `friidump -p` commands as readiness or cleanup
+probes. During validation, separate probe commands blocked in kernel I/O and
+required a power cycle of the external drive and USB bridge. The accepted run
+used FriiDump's internal ready-media check and internal STOP UNIT only.
+
+## Cross-flashed GDR-8050L GameCube/Wii procedure
+
+The validated physical unit required this sequence before a GameCube/Wii run:
+
+1. Put a readable Video DVD in the tray.
+2. Close the tray.
+3. Power on and connect the external drive.
+4. Wait until Linux identifies it as `HL-DT-ST DVD-ROM GDR8050L 0012`.
+5. Keep drive power and USB connected.
+6. Use the physical eject button.
+7. Replace the Video DVD with the target GameCube or Wii disc.
+8. Close the tray and wait for spin-up.
+9. Start FriiDump as the normal user with `cap_sys_rawio=ep` on the exact
+ validated executable.
+
+This boot-disc requirement is evidence for the validated cross-flashed unit. It
+is not a general claim for every GDR-8050L.
+
+On the validated JMicron `152d:2338` USB bridge, normal host media discovery
+started background reads that could block the USB/SCSI path before FriiDump
+opened the drive. The accepted run temporarily stopped UDisks and paused udev
+rule execution, created private device nodes from sysfs, ran FriiDump, required
+the external target to be disconnected, and then restored the host state.
+
+Do not disable UDisks or udev permanently. Use a reviewed, failure-safe
+quarantine workflow only when background host probing is proven to interfere.
+Record the original service state, restore it on every exit path, and disconnect
+the external target before queued udev work is released.
+
+If an optical command remains in process state `D`, signals cannot complete
+until the blocked kernel request returns. Power-cycle only the external drive
+and USB bridge. Leave unrelated optical drives installed.