Sun server asks firmware password after reboot (at OBP)

I came across a situation where I had to add a storage box to one Sun server. While reboot, the system doesn't want to come up and stucks at "Firmware password". After sometime, I figured out that it was because of firmware security option set at OBP level.

In this case, I booted the server normally (without a reconfiguration reboot) and then came to OS prompt.

Earlier:
# eeprom | grep security-mode
security-mode=command


Later: (to resolve/disable firmware password)
# eeprom security-mode=none
# eeprom | grep security-mode
security-mode=none