Subject: Re: [PATCH 1/2] powerpc/85xx: fix problem that prevents PHYS_64BIT from configurable

From: Timur Tabi <[email-masked]>
Date: Fri, 17 Feb 2012 15:17:51 -0600

Benjamin Herrenschmidt wrote:
> Sorry, I fail to see how... it basically makes all those boards
> non-functional even when enabled...

So you're saying that if we allow 32-bit address spacing for a particular
board, then we must provide a 32-bit DTS to go with it?

I was hoping to use the defconfig to force 36-bit, so that we can have a
32-bit option if we want.  Just because we don't put a 32-bit DTS in the
upstream kernel, that doesn't mean that no one is allowed to have a 32-bit
kernel.

> What's wrong with the current scheme ?

It prevents the possibility of creating an "optimized" 32-bit address
environment, for people who have <= 2GB of DDR on the board.  If we want
to ship a 32-bit DTS and 32-bit U-Boot on our BSP, then we'll need to
patch the Kconfig to remove the "select" line.

-- 
Timur Tabi
Linux kernel developer at Freescale