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

From: Rob Clark
Date: Fri Dec 23 2011 - 12:10:09 EST


On Fri, Dec 23, 2011 at 4:00 AM, Semwal, Sumit <sumit.semwal@xxxxxx> wrote:
> On Wed, Dec 21, 2011 at 10:57 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote:
>> On Tuesday 20 December 2011, Daniel Vetter wrote:
>>> > I'm thinking for a first version, we can get enough mileage out of it by saying:
>>> > 1) only exporter can mmap to userspace
>>> > 2) only importers that do not need CPU access to buffer..
>
> Thanks Rob - and the exporter can do the mmap outside of dma-buf
> usage, right?

Yes

> I mean, we don't need to provide an mmap to dma_buf()
> and restrict it to exporter, when the exporter has more 'control' of
> the buffer anyways.

No, if it is only for the exporter, it really doesn't need to be in
dmabuf (ie. the exporter already knows how he is)

BR,
-R

>>
> BR,
> ~Sumit.
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