Re: [PATCH] ARM: pxa: Move iotable mapping inside vmalloc region

From: Ezequiel Garcia
Date: Sun Nov 24 2013 - 17:56:12 EST


On Sun, Nov 24, 2013 at 12:41:25PM +0000, Russell King - ARM Linux wrote:
> On Sun, Nov 24, 2013 at 09:36:11AM -0300, Ezequiel Garcia wrote:
> > In order to remove the following ugly message:
> >
> > BUG: mapping for 0x00000000 at 0xff000000 out of vmalloc space
> >
> > the iotable mappings should be re-located inside the vmalloc
> > region. Such move was introduced at commit:
> >
> > commit 0536bdf33faff4d940ac094c77998cfac368cfff
> > Author: Nicolas Pitre <nicolas.pitre@xxxxxxxxxx>
> > Date: Thu Aug 25 00:35:59 2011 -0400
> >
> > ARM: move iotable mappings within the vmalloc region
> >
> > While at it, let's add some nicer defines to make the code
> > more readable.
> >
> > Cc: Nicolas Pitre <nicolas.pitre@xxxxxxxxxx>
> > Signed-off-by: Ezequiel Garcia <ezequiel.garcia@xxxxxxxxxxxxxxxxxx>
>
> NAK. I'm guessing that you haven't properly tested this. Grep for
> UNCACHED_PHYS_0, and what you'll find is that your change will break
> standby and suspend on all PXA platforms.

Right, I fail to grep about this properly, sorry about that.
Anyway, after grepping for 'UNCACHED' and doing some testings
I found a few interesting things.

First, UNCACHED_PHYS_0 seems to be used by PXA27xx and PXA25xx. The
board I have here is PXA3xx, so there's no way I can test anything.

Question: Should we add an #ifdef around the mapping, or is that
just pure churn?

Second, suspend/resume seems broken on my CM-X300 board, or at least
the wake-up. It enters suspend/standby but then never seem to wake.
Maybe I'm not pushing the right button, but according to the reference
guide the SW2 (connected to EXTWAKE#) should do the trick.

Ideas?
--
Ezequiel GarcÃa, Free Electrons
Embedded Linux, Kernel and Android Engineering
http://free-electrons.com
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