[PATCH 00/14] Fix issues with ARMv6+v6k+v7 kernels

[Tony Lindgren]

* Nicolas Pitre <nicolas.pitre at linaro.org> [110209 08:44]:
> On Wed, 9 Feb 2011, Russell King - ARM Linux wrote:
> 
> > On Wed, Feb 09, 2011 at 08:24:21AM -0800, Tony Lindgren wrote:
> > > * Santosh Shilimkar <santosh.shilimkar at ti.com> [110209 01:59]:
> > > > > From: Dave Martin [mailto:dave.martin at linaro.org]
> > > > >
> > > > > You could also have a "v7+" unified kernel -- i.e., supporting
> > > > > OMAP3+4+SMP.
> > > > > This is what we currently do in Linaro, since we're focusing on v7
> > > > > and above.
> > > > >
> > > > This sounds good way forward considering future OMAP architectures
> > > > as well.
> > > > 
> > > > But I let Tony comment on this idea.
> > > 
> > > AFAIK these issues will be hopefully sorted out by the time the
> > > next merge window opens. For the -rc cycle, disabling SMP in
> > > config if ARMv6 is selected should do the trick.
> > 
> > That's not soo easy - as we don't know in the Kconfig whether we include
> > ARMv6 rather than ARMv6K.  It's exactly the same problem I ran into which
> > inflated the v6v7 patchset.
> > 
> > Maybe the best thing to do is:
> > 
> > config CPU_32v6K
> >         bool "Support ARM V6K processor extensions" if !SMP
> >         depends on CPU_V6 || CPU_V7
> >         default y if SMP && !(ARCH_MX3 || ARCH_OMAP2)
> > 
> > drop the ' && !(ARCH_MX3 || ARCH_OMAP2)' and just let people run into the
> > resulting undefined instruction traps if they try to run the kernel on
> > V6 non-K hardware.  Not ideal, but I don't see any other 'simple' solution
> > to this.
> 
> This should be good enough.  We're looking for a temporary stopgate 
> solution to prevent people from corrupting their data, and the real fix 
> will be available in the next kernel.

OK. This patch will be needed anyways for the real fixes. And no temporary
apply-undo type patching needed. The only drawback is that omap2420 and
2430 won't boot with omap2plus_defconfig, but that will be only for a
few weeks.

Acked-by: Tony Lindgren <tony at atomide.com>