On Thu, Aug 20, 2020 at 07:33:48PM +0200, Tomasz Figa wrote:

quoted

It wasn't meant to be too insulting, but I found this out when trying
to figure out how to just disable it.  But it also ends up using
the actual dma attr flags for it's own consistency checks, so just
not setting the flag did not turn out to work that easily.

Yes, sadly the videobuf2 ended up becoming quite counterintuitive
after growing for the long years and that is reflected in the design
of this feature as well. I think we need to do something about it.

So I'm about to respin the series and wonder how we should proceed.
I've failed to come up with a clean patch to keep the flag and make
it a no-op.  Can you or your team give it a spin?

Also I wonder if the flag should be renamed from NON_CONSISTENT
to NON_COHERENT - the consistent thing is a weird wart from the times
the old PCI DMA API that is mostly gone now.