Re: [RFC PATCH v3] irqchip: Add support for Tango interrupt controller

From: Marc Gonzalez
Date: Wed Jan 20 2016 - 11:24:33 EST

On 20/01/2016 17:10, Måns Rullgård wrote:

> Marc Zyngier wrote:
>>> + if (of_property_read_u32(node, "reg", &ctl))
>>> + panic("%s: failed to get reg base", node->name);
>>> +
>>> + chip = kzalloc(sizeof(*chip), GFP_KERNEL);
>>> + chip->ctl = ctl;
>>> + chip->base = base;
> As I said before, this assumes the outer DT node uses a ranges
> property. Normally reg properties work the same whether they specify an
> offset within an outer "ranges" or have a full address directly. It
> would be easy enough to make this work with either, so I don't see any
> reason not to.

IIRC, I was told very early in the review process that the ranges prop
was mandatory. Lemme look for it... It was Arnd:

> You are missing a ranges property that describes what address
> space these addresses are in.
> 'ranges;' would be wrong here, as the interrupt controller is
> not a bus. If you have no ranges property, the bus is interpreted
> as having its own address space with no relation to the parent bus
> (e.g. an I2C bus uses addresses that are not memory mapped).
> Just list the addresses that are actually decoded by child
> devices here.

Did I misunderstand?