All of lore.kernel.org
 help / color / mirror / Atom feed
From: Matteo Fortini <matteo.fortini@mta.it>
To: linux-ppc list <linuxppc-dev@ozlabs.org>
Subject: MPC512x DMA to PCI dev
Date: Wed, 11 Mar 2009 13:11:44 +0100	[thread overview]
Message-ID: <49B7AA80.2030501@mta.it> (raw)

Hi all,
I'm trying to send some data through DMA from a memory buffer to a PCI 
video card VRAM.

While I got that I need to alloc the src buffer through 
dma_alloc_coherent, I don't understand which address I should give as 
the dst address.

I tried both the mapped hw address and an address received from 
pci_map_single, but even if the DMA transfer completes "correctly", I 
have the wrong data in the VRAM in the end.

I read about all the PCI DMA manuals, but it seems they are for letting 
some external DMA device on the PCI bus read/write from/to the main memory.

How do you do that?

Thanks,
Matteo

             reply	other threads:[~2009-03-11 12:43 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-03-11 12:11 Matteo Fortini [this message]
2009-03-12 10:51 ` MPC512x DMA to PCI dev Matteo Fortini

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=49B7AA80.2030501@mta.it \
    --to=matteo.fortini@mta.it \
    --cc=linuxppc-dev@ozlabs.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.