Plugging in a PoE phone into a Catalyst 3550 results in the phone not powering up and the following being logged in the console.
%ILPOWER-3-CONTROLLER_PORT_ERR: Controller port error, Interface Fa0/10: Power given, but link is not up
The fix is to delay the switch shutting down the interface, which gives the phone enough time to activate the link. The following is required under the interface providing PoE.
(config-if)#power inline delay shutdown 20 initial 100