Root Hub Transaction Translators

configname: CONFIG_USB_EHCI_ROOT_HUB_TT

Linux Kernel Configuration
└─>Device Drivers
└─>USB support
└─>Root Hub Transaction Translators
In linux kernel since version 2.6.20 (release Date: 2007-02-04)  
Some EHCI chips have vendor-specific extensions to integrate
transaction translators, so that no OHCI or UHCI companion
controller is needed. It's safe to say "y" even if your
controller doesn't support this feature.

This supports the EHCI implementation that's originally
from ARC, and has since changed hands a few times.