When you boot the Oracle Solaris OS with a USB 3.0 device installed in one of the rear USB ports of a SPARC T5-2 server, the following message might be displayed.
WARNING /pci@300/pci@1/pci@0/pci@4/pci@0/pci@6/usb@0
(xhci0): Connecting device on port 7 failed
Workaround: You can safely ignore this message.