So, developers implicitly or explicitly copied in this thread that might be considering the usage of dmabuf on proprietary drivers should consider this email as a formal notification of my viewpoint: e. g. that I consider any attempt of using DMABUF or media core/drivers together with proprietary Kernelspace code as a possible GPL infringement.
Though that does beg the question why you care about this patch :-)
Because my legal advice is to object and remind people who suggest otherwise. There are specific reasons to do so around estoppel and willful infringement.
It's not a case of objections anyway - if the _GPL matters then it's a licensing change so you need the approval of everyone whose code is involved. At that point I think Nvidia are starting in the wrong place and need to start with a collection of vendors corporate legal contacts and then work down the call tree involved.
Alan