+++ Hector Oron [2010-07-28 13:25 +0100]:
> On Thu, Jul 22, 2010 at 04:16:18PM +0100, Wookey wrote:
> > We've always had more than 256Mb RAM but not been able to make one
> > kernel that would access it all on both >256Mb and <=256Mb builds.
> >
> > This patch
> > http://git.kernel.org/?p=linux/kernel/git/marex/pxa-linux-2.6.git;a=commit;h=9ee18023466d30e3847a77c82a1e776fb3cf02fc
> >
> > enables exactly that for another pxa270 board.
> >
> > I _think_ it's exactly what we need and is all of 10 lines. But I
> > could be wrong.
> Just notice that 128Mb RAM bank above 256Mb will run at a half of
> the speed. According to Marek (guy wrote the patch - expect news from
> him soon), PXA is able to keep up with it.
Or, more explicitly, the memory errors NickB found when enabling that
bank as a ramdisk, and which were also observed when using it as plain
system RAM, go away if you set that bank to run at half speed, which
the PXA seems qwuite happy to do.
This suggests genuine hardware dodginess in there somewhere. I wonder
what the real-world effect on speed is of having the top 1/3rd of your
RAM slower than the rest? Hopefully less than the effect of having
another 128MB to play with.
Wookey
--
Principal hats: Linaro, Emdebian, Wookware, Balloonboard, ARM
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