Comment by whytevuhuni

> wasn't this a DMA patch?

Although it was a DMA patch, it was not in the DMA subsystem that Christoph maintains. More specifically, it was not a file in the kernel/dma directory, but rather a file in the rust/kernel directory, which is where the Rust subsystem lives.

The Rust code is essentially a consumer of the DMA public API, much like many other subsystems in the kernel that consume it.

This is why some people are upset and confused about the situation; he added a Nacked-by tag to a patch that is outside his area. He had good reasons for it, but it was hard to see them based on the way he wrote his replies.