VFP handling in multiplatform feroceon kernels

Catalin Marinas
2014-06-24T13:42:49Z

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