On Thursday 03 April 2008, Jeffrey Watts wrote:
Copyright holders have the ability to grant permission to use their IP in ways different from their copyright. You could argue that Greg could try and sue nVidia for its infringement, but don't you think that it is an absurd effort and unlikely to succeed given that Torvalds wouldn't be party to it? I'm certainly no IP lawyer, but I'd think that a court would have a hard time determining injury without a claim of one by Mr Torvalds.
Torvalds is not the only copyright holder, and could do nothing to grant nVidia permission beyond the GPL 2 at this point. I see no reason his testimony would be needed in court. Did he appear for the D-link lawsuit in which the GPL was upheld? From reading the proceedings, it seems to me to have been specifically copyright on the Linux kernel that was addressed.