I agree with the logic Airlied made about Robert's patch. This is an important interface where it's not something you want to force closed source vendors to recreate and have things be an incompatible mess. This would cause a disaster for end users in the long rung... As for Airlied's mentioning of finding out the author's intention. This requires a chain of events to find out what exactly is going on... With this said, I will go ahead and post a quick chain of events to figure out what is going on with this section of code so that this can get resolved as quickly as possible...
So far, The only two that even suggested that this API be made EXPORT_SYMBOL_GPL is Konrad Wilk and Arnd Bergmann. That said, Of course Semwil will agree since the whole discussion of this occurred over a 5 day span, and then a delay of about 12 days before the final RFC submission was made.
The initial Framework and build up of the dma-buf interface: ( August 10th 2011) * [Linaro-mm-sig] [RFC] dma-shared-buf: Add buffer sharing framework http://lists.linaro.org/pipermail/linaro-mm-sig/2011-August/000509.html
* [Linaro-mm-sig] [RFC v2] dma-buf: Add buffer sharing framework http://lists.linaro.org/pipermail/linaro-mm-sig/2011-September/000616.html
* [Linaro-mm-sig] [RFC v3] dma-buf: Add buffer sharing framework http://lists.linaro.org/pipermail/linaro-mm-sig/2011-September/000661.html
* [Linaro-mm-sig] [RFC 1/2] dma-buf: Introduce dma buffer sharing mechanism http://lists.linaro.org/pipermail/linaro-mm-sig/2011-October/000692.html
* [Linaro-mm-sig] [RFC v2 1/2] dma-buf: Introduce dma buffer sharing mechanism http://lists.linaro.org/pipermail/linaro-mm-sig/2011-December/000810.html
At this point it's December 2nd, and clearly it's been about 113 days since the initial interface suggestion. At this point is where the changes where suggested...
Konrad - Makes initial suggestion ( was first response to this thread ) http://lists.linaro.org/pipermail/linaro-mm-sig/2011-December/000812.html
Arnd - Agrees with Konrad (same thread ) http://lists.linaro.org/pipermail/linaro-mm-sig/2011-December/000815.html
Semwil - Agrees with the other two ( same thread on December 7th) http://lists.linaro.org/pipermail/linaro-mm-sig/2011-December/000830.html
Then the final seal on this transaction appears on the RFC V3 for this version of the path that appeared December 19th... * [Linaro-mm-sig] [RFC v3 1/2] dma-buf: Introduce dma buffer sharing mechanism http://lists.linaro.org/pipermail/linaro-mm-sig/2011-December/000880.html
There's a closing statement that mentions this change ( However, there is no challenges made) * [Linaro-mm-sig] [ACTIVITY] Status of memory management closing 11.12 http://lists.linaro.org/pipermail/linaro-mm-sig/2011-December/000896.html
Now the patch submission itself... * [Linaro-mm-sig] [PATCH 1/3] dma-buf: Introduce dma buffer sharing mechanism http://lists.linaro.org/pipermail/linaro-mm-sig/2011-December/000922.html
Finally, this as a whole is sent to another mailing list... * [DRI-devel] [git pull] dma-buf tree ( January 6th, 2012) http://lists.freedesktop.org/archives/dri-devel/2012-January/017984.html
The first challenge of the change appears.... * [DRI-devel] [PATCH] dma-buf: Use EXPORT_SYMBOL ( January 17th, 2012) http://lists.freedesktop.org/archives/dri-devel/2012-January/018250.html