> +++ 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.
>
Ta, sorry posted a note about ram errors before I read this. Nick

> Wookey