Messages in this thread | | | Date | Thu, 9 Jun 2011 11:38:11 +0200 | Subject | Re: Why move all map_sg/unmap_sg for slave channel to its client? | From | Linus Walleij <> |
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On Thu, Jun 9, 2011 at 8:54 AM, viresh kumar <viresh.kumar@st.com> wrote:
> I thought map_sg/unmap_sg for slave channels will be handled according > to the flags passed in prep_slave_sg(). But then i found following patch: > (...) > I don't have much knowledge about that discussion, but i think this should be left > configurable. > If the client wants to control map/unmap then it can simply pass > DMA_COMPL_SKIP_DEST_UNMAP | DMA_COMPL_SKIP_SRC_UNMAP in flags. I didn't wanted to > skip this in my driver and so i don't pass them.
What if the same driver is used on many different platforms like say drivers/tty/serial/amba-pl011.c, and some of the platforms using it has DMA engines that does not implement mapping/unmapping of the passed sglist?
In that case I think you have to modify all drivers in drivers/dma/* to do this mapping, and then you could just make it a required behaviour and skip the flags altogether.
But apparently that approach was blocked at one point so let's see what the others say.
Yours, Linus Walleij
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