From: Vinod Koul <vkoul@kernel.org>
To: Lars-Peter Clausen <lars@metafoo.de>
Cc: Adrian Larumbe <adrian.martinezlarumbe@imgtec.com>,
dmaengine@vger.kernel.org, michal.simek@xilinx.com,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 0/4] Expand Xilinx CDMA functions
Date: Fri, 23 Apr 2021 18:54:59 +0530 [thread overview]
Message-ID: <YILKq+jNZZSs37xa@vkoul-mobl.Dlink> (raw)
In-Reply-To: <c2876f2c-beb2-f159-9b61-d69ae6b8275a@metafoo.de>
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
next prev parent reply other threads:[~2021-04-23 13:25 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-23 1:19 [PATCH 0/4] Expand Xilinx CDMA functions Adrian Larumbe
2021-04-23 1:19 ` [PATCH 1/4] dmaengine: xilinx_dma: Add extended address support in CDMA Adrian Larumbe
2021-04-23 1:19 ` [PATCH 2/4] dmaengine: xilinx_dma: Add channel configuration setting callback Adrian Larumbe
2021-04-23 1:19 ` [PATCH 3/4] dmaengine: xilinx_dma: Add CDMA SG transfer support Adrian Larumbe
2021-04-23 1:19 ` [PATCH 4/4] dmaengine: xilinx_dma: Add device synchronisation callback Adrian Larumbe
2021-04-23 6:33 ` Lars-Peter Clausen
2021-04-23 11:49 ` [EXTERNAL] " Adrian Larumbe
2021-04-23 9:17 ` [PATCH 0/4] Expand Xilinx CDMA functions Lars-Peter Clausen
2021-04-23 11:38 ` [EXTERNAL] " Adrian Larumbe
2021-04-23 13:24 ` Vinod Koul [this message]
2021-04-23 13:51 ` Lars-Peter Clausen
2021-04-23 14:36 ` [EXTERNAL] " Adrian Larumbe
2021-04-23 17:20 ` Vinod Koul
2021-06-01 10:29 ` radhey pandey
2021-07-02 14:23 ` [EXTERNAL] " Adrian Larumbe
2021-07-05 3:53 ` Vinod Koul
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=YILKq+jNZZSs37xa@vkoul-mobl.Dlink \
--to=vkoul@kernel.org \
--cc=adrian.martinezlarumbe@imgtec.com \
--cc=dmaengine@vger.kernel.org \
--cc=lars@metafoo.de \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=michal.simek@xilinx.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).