Re: [PATCH] powerpc/npu-dma: Remove NPU DMA ops

[Christoph Hellwig]

On Wed, Oct 31, 2018 at 12:09:29AM +1100, Benjamin Herrenschmidt wrote:
> On Tue, 2018-10-30 at 13:58 +0100, Christoph Hellwig wrote:
> > Please take my patch instead.  We have a kernel polcity to not keep
> > dead code around, and everyone including Linus and the attending IBMers
> > confirmed this.
> 
> Let's call a cat a cat ... ;-)
> 
> It's not *dead* code. It's code that is used by an out of tree driver
> (which also happen not to be open source).

Which clearly makes it a derived work of the kernel if it uses an
interface just create for it, and thus even more important to remove
it to not get anyone into legal trouble.