[PATCH 0/4] Expand Xilinx CDMA functions
Vinod Koul
vkoul at kernel.org
Fri Apr 23 14:24:59 BST 2021
On 23-04-21, 11:17, Lars-Peter Clausen wrote:
>
> It seems to me what we are missing from the DMAengine API is the equivalent
> of device_prep_dma_memcpy() that is able to take SG lists. There is already
> a memset_sg, it should be possible to add something similar for memcpy.
You mean something like dmaengine_prep_dma_sg() which was removed?
static inline struct dma_async_tx_descriptor *dmaengine_prep_dma_sg(
struct dma_chan *chan,
struct scatterlist *dst_sg, unsigned int dst_nents,
struct scatterlist *src_sg, unsigned int src_nents,
unsigned long flags)
The problem with this API is that it would work only when src_sg and
dst_sg is of similar nature, if not then how should one go about
copying...should we fill without a care for dst_sg being different than
src_sg as long as total data to be copied has enough space in dst...
We can always add this back if we have in-kernel user but the semantics
of the API needs to be thought thru
Thanks
--
~Vinod
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