Apple has posted Thunderbolt Firmware Update v1.1 for the mid-2012 MacBook Pro on Tuesday.
It addresses an issue with MacBook Pro (mid 2012) and some Thunderbolt cables that may prevent bus-powered Thunderbolt devices from functioning properly. The update requires OS X 10.7.4 or higher.
Thunderbolt Firmware Update v1.1 is available through the Mac OS X Software Update app, or as a downloadable installer at http://support.apple.com/kb/DL1612 .