[PATCH] arm64/acpi: Add fixup for HPE m400 quirks

[msalter@redhat.com (Mark Salter)]

On Fri, 2018-06-15 at 11:15 -0700, Geoff Levand wrote:
> Hi Mark,
> 
> On 06/15/2018 10:33 AM, Mark Salter wrote:
> > On Fri, 2018-06-15 at 10:17 -0700, Geoff Levand wrote:
> > > > > +            MIDR_IMPLEMENTOR(read_cpuid_id()) == ARM_CPU_IMP_APM) {
> > > > 
> > > > How is the CPU implementer relevant?
> > > 
> > > That was just a copy of what other fixes had.  Should I remove it?
> > 
> > It was there because HPE ProLiant strings are generic and you may end up
> > disabling platforms which would otherwise work. It is the ProLiant system
> > based on the APM chipset which is the problem. Thus the check for cpu
> > implementor.
> 
> Your original fix that had this cpu implementor check was in the main
> ACPI code, so would be built for other arches.  This is now in
> arch/arm64/kernel/acpi.c, which will only be built for arm64.  Is that
> enough to limit it, or do we still need the check?

The original code was protected by #ifdef ARM64. But yes, HPE has announced
another aarch64 ProLiant system based on Cavium ThunderX2. So we need to
allow everything but the APM XGene based ProLiant products.