From: arnd@arndb.de (Arnd Bergmann)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 01/10] ARM: change ARM_DMA_ZONE_SIZE into a variable
Date: Thu, 7 Jul 2011 19:40:24 +0200 [thread overview]
Message-ID: <201107071940.24964.arnd@arndb.de> (raw)
In-Reply-To: <81e4ac16-db7b-47a0-9f93-632a5d9f898d@VA3EHSMHS028.ehs.local>
On Thursday 07 July 2011 19:08:38 John Linn wrote:
> > There is a way to specify DMA address ranges in the device tree,
> though
> > I forgot the exact format. It comes down to saying the device sees
> > memory range XXX to YYY as its local address AAA to BBB. We could use
> > that information at boot time to determine what the largest range
> > of memory is that is visible by all devices (and hope that it's at
> > the start of physical memory).
>
> If I'm following this right....
>
> We have a hole at the start of physical memory (when it's at 0) so that
> DMA can't DMA into it. Sounds like that won't work for us?
A whole in physical memory should not be a problem. It's only a problem
if you have a device that can do DMA only to to some memory range that
is not the start of your RAM, e.g. only the second 256MB but not the first.
Arnd
next prev parent reply other threads:[~2011-07-07 17:40 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-06 2:30 [PATCH 01/10] ARM: change ARM_DMA_ZONE_SIZE into a variable Nicolas Pitre
2011-07-06 2:30 ` [PATCH 02/10] ARM: add dma_zone_size to the machine_desc structure Nicolas Pitre
2011-07-06 23:10 ` Russell King - ARM Linux
2011-07-07 2:59 ` Nicolas Pitre
2011-07-06 2:30 ` [PATCH 03/10] ARM: mach-davinci: move from ARM_DMA_ZONE_SIZE to mdesc->dma_zone_size Nicolas Pitre
2011-07-06 2:30 ` [PATCH 04/10] ARM: mach-h720x: " Nicolas Pitre
2011-07-06 2:30 ` [PATCH 05/10] ARM: mach-ixp4xx: " Nicolas Pitre
2011-07-06 23:12 ` Russell King - ARM Linux
2011-07-07 3:31 ` Nicolas Pitre
2011-07-06 2:30 ` [PATCH 06/10] ARM: mach-pxa: " Nicolas Pitre
2011-07-06 2:30 ` [PATCH 07/10] ARM: mach-realview: " Nicolas Pitre
2011-07-06 23:15 ` Russell King - ARM Linux
2011-07-07 3:59 ` Nicolas Pitre
2011-07-06 2:30 ` [PATCH 08/10] ARM: mach-sa1100: move " Nicolas Pitre
2011-07-06 2:30 ` [PATCH 09/10] ARM: mach-shark: " Nicolas Pitre
2011-07-06 2:30 ` [PATCH 10/10] ARM: ARM_DMA_ZONE_SIZE is no more Nicolas Pitre
2011-07-06 2:48 ` [PATCH 01/10] ARM: change ARM_DMA_ZONE_SIZE into a variable Barry Song
2011-07-06 3:12 ` Nicolas Pitre
2011-07-06 23:09 ` Russell King - ARM Linux
2011-07-07 2:50 ` Nicolas Pitre
2011-07-07 16:17 ` Arnd Bergmann
2011-07-07 17:08 ` John Linn
2011-07-07 17:40 ` Arnd Bergmann [this message]
2011-07-08 8:59 ` Russell King - ARM Linux
2011-07-08 13:58 ` John Linn
2011-07-08 16:23 ` Russell King - ARM Linux
2011-07-07 18:15 ` Grant Likely
2011-07-06 23:04 ` Russell King - ARM Linux
2011-07-07 2:46 ` Nicolas Pitre
2011-07-08 12:14 ` Russell King - ARM Linux
2011-07-08 20:30 ` Russell King - ARM Linux
2011-07-09 8:12 ` Russell King - ARM Linux
2011-07-09 8:13 ` Russell King - ARM Linux
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=201107071940.24964.arnd@arndb.de \
--to=arnd@arndb.de \
--cc=linux-arm-kernel@lists.infradead.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.