From: grant.likely@secretlab.ca (Grant Likely)
To: linux-arm-kernel@lists.infradead.org
Subject: RFC: ARM Boot standard for passing device tree blob
Date: Fri, 26 Mar 2010 12:13:39 -0600 [thread overview]
Message-ID: <fa686aa41003261113o7cd8612eh9b51904114902a3a@mail.gmail.com> (raw)
In-Reply-To: <4BACF238.3040405@firmworks.com>
On Fri, Mar 26, 2010 at 11:43 AM, Mitch Bradley <wmb@firmworks.com> wrote:
> Catalin Marinas wrote:
>> On Thu, 2010-03-25 at 21:04 +0000, Russell King - ARM Linux wrote:
>>> On Wed, Mar 24, 2010 at 09:11:56AM -0600, Grant Likely wrote:
>>>> *IRQs disabled
>>>> *MMU off
>>>> *Instruction cache either on or off
>>>> *Data cache turned off
>>>
>>> Would recommend saying "Data cache(s) turned off" so that L2 cache is
>>> included.
>>
>> There are platforms where the L2 cache is turned on by the boot monitor
>> (secure monitor) and Linux has no control over it (I think OMAP).
>
> What is the reason for turning off the data caches? ?Leaving all caches
> turned on and coherent with one another has always worked well for me at the
> interface from firmware to a booted program.
Data cache off is specified in Documentation/arm/Booting in the Linux
source tree and I used that document as a starting point to get
discussion going. I don't have a technical argument either way.
Russell, what is the reason for having the data cache off?
g.
next prev parent reply other threads:[~2010-03-26 18:13 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-24 15:11 RFC: ARM Boot standard for passing device tree blob Grant Likely
2010-03-25 21:04 ` Russell King - ARM Linux
2010-03-25 23:40 ` David Gibson
2010-03-26 0:23 ` Jeremy Kerr
2010-03-26 3:24 ` Grant Likely
2010-03-26 13:37 ` Catalin Marinas
2010-03-26 17:43 ` Mitch Bradley
2010-03-26 18:13 ` Grant Likely [this message]
2010-03-26 19:30 ` Nicolas Pitre
2010-03-26 19:52 ` Grant Likely
2010-03-26 23:03 ` Russell King - ARM Linux
2010-03-29 11:24 ` Dave P. Martin
2010-03-30 0:26 ` Jamie Lokier
2010-03-30 13:32 ` Dave P. Martin
2010-03-26 23:00 ` Russell King - ARM Linux
2010-03-31 1:10 ` Ben Dooks
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