From: "shesha bhushan" <bhushan_vadulas@hotmail.com>
To: linux-kernel@vger.kernel.org
Subject: What does pci_map_single do
Date: Wed, 19 Feb 2003 03:10:23 +0000 [thread overview]
Message-ID: <F156VoTsP4rQLlRe7by0003d952@hotmail.com> (raw)
Hi All,
I wanted to use DMA in my device driver.
1. pci_map_single will transfer the data from RAM (kernel area) to the
hardware accessible area and will provide with a pointer which can then be
passed to the hardware.
2. In the above function the "size" parameter indicates the amount of DMA
transfer.
Am I correct in the above two points? If I am wrong please correct me.
In the Linux Device driver book (page 408), he says, data must be explicitly
flushed from the processor cache. And data flushed this way is not avaliable
to the device.
This means that we must flush the processor cache before calling
pci_map_single. How can we achieve this.
Thanking You
Shesha
_________________________________________________________________
The new MSN 8: advanced junk mail protection and 2 months FREE*
http://join.msn.com/?page=features/junkmail
reply other threads:[~2003-02-19 3:01 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=F156VoTsP4rQLlRe7by0003d952@hotmail.com \
--to=bhushan_vadulas@hotmail.com \
--cc=linux-kernel@vger.kernel.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
all inboxes | Powered by JetHome®