mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: "Frank Buss" <fb@frank-buss.de>
To: "'Linux Kernel Mailing List'" <linux-kernel@vger.kernel.org>
Cc: <rmk+lkml@arm.linux.org.uk>
Subject: RE: Problems with dma_mmap_writecombine on mach-pxa
Date: Wed, 23 Feb 2005 02:36:23 +0100	[thread overview]
Message-ID: <20050223013624.346885B8C4@frankbuss.de> (raw)
In-Reply-To: 

Russell King <rmk+lkml@arm.linux.org.uk> wrote:

> Since we map the whole lot in one go, if you get one page, there's no
> reason why you shouldn't get the lot.  This is why I'm wondering if
> it has something to do with your other modifications.

my colleage has found the bug: in the function dma_mmap in 
arch/arm/mm/consistent.c the call to remap_pfn_range uses 
user_size in PAGE_SIZE units, but looks like it is expected 
in bytes. When using (user_size << PAGE_SHIFT), it works.

I don't know, where to fix it: Should the lower level calls 
get the size in bytes (most function arguments in Linux 
kernel sources are not commented), this means fixing the 
dma_mmap, or should PAGE_SIZE be used, then the lower level 
functions needs to be fixed.

-- 
Frank Buß, fb@frank-buss.de
http://www.frank-buss.de, http://www.it4-systems.de


             reply	other threads:[~2005-02-23  1:36 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-02-23  1:36 Frank Buss [this message]
  -- strict thread matches above, loose matches on Subject: below --
2005-02-17 17:51 Frank Buss
2005-02-17 18:12 ` Russell King
2005-02-17 19:14   ` Frank Buss
2005-02-17 19:58     ` Russell King
2005-02-18 18:07   ` Frank Buss

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=20050223013624.346885B8C4@frankbuss.de \
    --to=fb@frank-buss.de \
    --cc=linux-kernel@vger.kernel.org \
    --cc=rmk+lkml@arm.linux.org.uk \
    /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®