This only happens when OTG USB is connected to another USB host, regardless if c9100000.usb is in host or device mode. The board is pulling power from the USB-connected host. Even if I unplug the main power the AML board power stays lit and does not reboot when main power is reapplied. Is it possible to disable power to/from c9100000.usb? Will re-enabling watchdog matter?
Being able to reboot even when in OTG mode is pretty important.
Update #2: I taped over the power and ground pins on usb cable which means I can now shutdown by only pulling main power but now device will not boot at all while cable is inserted. If I insert doctored cable after boot, it works great as OTG client to host system.
With a standard USB plugged into this port the device reboots normally.
If there is reverse power going to the 5V on USB, the system tries to reset by turning off the regulators. However, it’s unable to reset the chip because the 5V is on when it should be off. Watchdog is the only way.