Steam Machines, mini-computers meant to bring the Steam platform into the living room, will not support suspend/resume features. This is particularly disheartening as both the Xbox One and PlayStation 4 have such features. PCs, which Steam primarily runs on, have had this feature for ages.
“Given the state of hardware and software support throughout the graphics stack on Linux we didn’t think we could make this reliable,” explained a Valve employee on Github.
The problem is apparently in the way that Linux handles USB devices on Suspend/Resume. When resuming a game, controllers become unresponsive, essentially being seen as disconnected. Hilariously enough, several programmers have stepped forward happily offering to fix this issue for Valve… for a price.
Source: Gamespot