On 30/03/16 19:18, Boris Brezillon wrote:
On Wed, 30 Mar 2016 09:51:43 -0700
Mark Brown <broonie@xxxxxxxxxx> wrote:
On Wed, Mar 30, 2016 at 05:39:51PM +0200, Boris Brezillon wrote:
sg_alloc_table_from_buf() provides an easy solution to create an sg_table
from a virtual address pointer. This function takes care of dealing with
vmallocated buffers, buffer alignment, or DMA engine limitations (maximum
DMA transfer size).
This seems nice. Should we also have a further helper on top of this
which will get constraints from a dmaengine, it seems like it'd be a
common need?
Yep, we could create a wrapper extracting dma_slave caps info,
converting it to sg_constraints and calling sg_alloc_table_from_buf().
But let's try to get this function accepted first, and I'll send another
patch providing this wrapper.
BTW, do you see other things that should be added in sg_constraints?
You could compare with the things Solaris uses to describe the
restrictions on a DMA binding ...
http://docs.oracle.com/cd/E23824_01/html/821-1478/ddi-dma-attr-9s.html#REFMAN9Sddi-dma-attr-9s
.Dave.
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