[PATCH v5 18/18] Documentation: ACPI for ARM64

[Catalin Marinas]

On Mon, Jan 05, 2015 at 08:16:30PM +0000, Arnd Bergmann wrote:
> On Monday 05 January 2015 13:13:02 Catalin Marinas wrote:
> > > since passing no DT tables to OS but
> > > acpi=force is missing is a corner case, we can do a follow up patch to
> > > fix that, does it make sense?
> > 
> > Not entirely. Why would no dtb and no acpi=force be a corner case? I
> > thought this should be the default when only ACPI tables are passed, no
> > need for an additional acpi=force argument.
> 
> We don't really support the case of only ACPI tables for now. The expectation
> is that you always have working DT support, at least for the next few years
> as ACPI features are ramping up, and without acpi=force it should not try
> to use ACPI at all.

So if both DT and ACPI are present, just use DT unless acpi=force is
passed. So far I think we agree but what I want to avoid is always
mandating acpi=force even when the DT tables are missing (in the long
run).

Now, what's preventing a vendor firmware from providing only ACPI
tables? Do we enforce it in some way (arm-acpi.txt, kernel warning etc.)
that both DT and ACPI are supported, or at least that dts files are
merged in the kernel first?

-- 
Catalin