From mboxrd@z Thu Jan  1 00:00:00 1970
From: catalin.marinas@arm.com (Catalin Marinas)
Date: Tue, 24 Jun 2014 14:42:49 +0100
Subject: VFP handling in multiplatform feroceon kernels
In-Reply-To: <7416978.W29blLsymn@wuerfel>
References: <7416978.W29blLsymn@wuerfel>
Message-ID: <20140624134249.GB4489@arm.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Tue, Jun 24, 2014 at 02:17:06PM +0100, Arnd Bergmann wrote:
> Since 3.16, we have the ability to build a multiplatform kernel
> that includes both kirkwood (feroceon) and some other ARMv5 CPU.
> 
> I accidentally stumbled over a bug in the VFP code that looks
> like it will break at least ARM9 VFP support if CPU_FEROCEON
> is also enabled, introduced by this (old) commit:

I would argue that the bug is in the CPU (feroceon). See the end of this
email:

http://www.spinics.net/lists/arm-kernel/msg41460.html

and my follow-up. Basically you can't avoid the conditional compilation
as Feroceon doesn't follow the VFP sub-architecture spec and doesn't
present itself as a different CPU from an _ARM_ 9. Unless things have
changed with Marvell's hardware implementation and they got a new id, I
suggest you don't enable this for multi-platform.

-- 
Catalin