Are they rejecting the driver because of it being open source? There are specific modules I use in my AMD card that require closed proprietary driver add-ons for example such as AMF.

Not defending the HDMI forum here, but perhaps Valve / AMD have a way of including a proprietary blob in SteamOS (I don't think most gamers would care)

>Valve strictly adheres to open-source drivers, but the HDMI Forum is unwilling to disclose the 2.1 specification.