Re: [PATCH v4 07/11] ARM: allow MULTIPLATFORM with !MMU

[Russell King - ARM Linux <linux@arm.linux.org.uk>]

On Fri, Apr 03, 2015 at 09:44:48PM +0200, Stefan Agner wrote:
> In order to support SoC with heterogenous CPU architectures (such
> as Freescale Vybrid/i.MXSX) it is preferable to use the same
> architecture (ARCH_MXC in this case) for the MMU enabled and !MMU
> CPU. Hence allow to select MULTIPLATFORM even without MMU.
> 
> Signed-off-by: Stefan Agner <stefan@agner.ch>
> ---
>  arch/arm/Kconfig | 21 ++++++++++-----------
>  1 file changed, 10 insertions(+), 11 deletions(-)
> 
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index 9f1f09a..636cb3f 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -230,7 +230,7 @@ config VECTORS_BASE
>  	  in size.
>  
>  config ARM_PATCH_PHYS_VIRT
> -	bool "Patch physical to virtual translations at runtime" if EMBEDDED
> +	bool "Patch physical to virtual translations at runtime" if EMBEDDED || (ARCH_MULTIPLATFORM && MMU)
>  	default y

This makes no sense.  Multiplatform MMU _requires_ this feature, so why
offer it to the user when multiplatform is enabled _and_ MMU is enabled?

Patch 7817/1 in the patch system tried doing something like you're trying
to do here - I wonder whether you've reviewed the mailing list for
previous discussions.

Given that it's Easter, I'm not going to re-state what I said last time
this came up, but instead leave you to do some research.  For example,
reading message id <20130819232411.GX23006@n2100.arm.linux.org.uk>...

Thanks.

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