Re: [PATCH] ARM: Keystone: Introduce Kconfig option to compile in typical Keystone features

From: Nishanth Menon
Date: Thu Jun 02 2016 - 08:35:31 EST


On 06/01/2016 06:26 PM, Santosh Shilimkar wrote:
[...]
>>> Side note on LPAE:
>>> For our current device tree and u-boot, LPAE is mandatory to bootup
>>> for current Keystone boards - but this is not a SoC requirement,
>>> booting without LPAE/HIGHMEM results in non-coherent DDR accesses.
>>
>> This sounds like a regression, I thought we had this working when
>> keystone was initially merged and we got both the coherent and
>> non-coherent mode working with the same DT.
>>
> Yes and it works. The coherent memory space itself is beyond 4GB so

Hmm... True, I just tested next-20160602 with mem_lpae set to 0 in
u-boot and it seems to boot just fine.

> I don't understand a requirement of having coherent memory without
> LPAE.

Looks like a messed up description on my end, Looks like I have to
update my automated test framework to incorporate the manual steps
involved.


--
Regards,
Nishanth Menon