[Linaro-mm-sig] [RFC v2 1/2] dma-buf: Introduce dma buffer sharing mechanism

Alan Cox alan at lxorguk.ukuu.org.uk
Fri Dec 9 06:24:05 PST 2011


> I still don't think that's possible. Please explain how you expect
> to change the semantics of the streaming mapping API to allow multiple
> mappers without having explicit serialization points that are visible
> to all users. For simplicity, let's assume a cache coherent system

I would agree. It's not just about barriers but in many cases where you
have multiple mappings by hardware devices the actual hardware interface
is specific to the devices. Just take a look at the fencing in TTM and
the graphics drivers.

Its not something the low level API can deal with, it requires high level
knowledge.

Alan


More information about the dri-devel mailing list