From: Matt Porter <porter@cox.net>
To: Waqar Ahmad <wahmad@snowshore.com>
Cc: linuxppc-embedded@lists.linuxppc.org
Subject: Re: problem with pci_alloc_consistent (it does work)
Date: Tue, 17 Sep 2002 16:16:51 -0700 [thread overview]
Message-ID: <20020917161651.B22545@home.com> (raw)
In-Reply-To: <200209171824.g8HIOaS17677@flyingfox.snowshore.com>; from wahmad@snowshore.com on Tue, Sep 17, 2002 at 02:24:35PM -0400
On Tue, Sep 17, 2002 at 02:24:35PM -0400, Waqar Ahmad wrote:
> Found the problem I was using phys_to_virt(..) to convert the
> physical address to virtual. Once I fixed that everything seems
> to be working now. so
Anybody confused by this should read and understand
Documentation/IO-mapping.txt. virt_to_phys/phys_to_virt
and virt_to_bus/bus_to_virt are only defined for usage on
system memory. This means statically mapped kernel memory.
The only way to reliably (cross platform) get a physical
address from pci_alloc_consistent is to hold on to your
dma_handle. This has been covered a number of times on lkml
with DavidM and might even be in the current DMA-mapping.txt
by now...but I doubt it. :)
Regards,
--
Matt Porter
porter@cox.net
This is Linux Country. On a quiet night, you can hear Windows reboot.
** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
prev parent reply other threads:[~2002-09-17 23:16 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-09-17 18:24 problem with pci_alloc_consistent (it does work) Waqar Ahmad
2002-09-17 23:16 ` Matt Porter [this message]
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=20020917161651.B22545@home.com \
--to=porter@cox.net \
--cc=linuxppc-embedded@lists.linuxppc.org \
--cc=wahmad@snowshore.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).