From: ranshalit@gmail.com (Ran Shalit)
To: kernelnewbies@lists.kernelnewbies.org
Subject: dma direction
Date: Sat, 7 Jan 2017 21:00:50 +0200 [thread overview]
Message-ID: <CAJ2oMhKRBPN1_sDwLnjsvQHjospqrKXQmc5gX4n+VU_Ypyn3Kg@mail.gmail.com> (raw)
Hello,
I read the DMA-API-HOWTO
https://www.kernel.org/doc/Documentation/DMA-API-HOWTO.txt
Which mainly talks about dma mapping APIs.
But I don't understand what's the meaning of DMA direction in context
of mapping.
As I understand this documentation talks about mapping of dma buffers
- NOT about triggering dma copy.
In order to do a dma copy, we should use sometlink like dmaengine, Right ?
So if dma mapping is not concerned with copying dma from cpu to device
(or vice versa), why does it talks about dma direction ?
Thanks,
Ran
reply other threads:[~2017-01-07 19:00 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
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=CAJ2oMhKRBPN1_sDwLnjsvQHjospqrKXQmc5gX4n+VU_Ypyn3Kg@mail.gmail.com \
--to=ranshalit@gmail.com \
--cc=kernelnewbies@lists.kernelnewbies.org \
/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).