Re: ACPI vs Device Tree - moving forward

[Guenter Roeck <linux@roeck-us.net>]

On 08/23/2013 07:38 PM, Matthew Garrett wrote:
> On Fri, Aug 23, 2013 at 06:47:23PM -0700, Guenter Roeck wrote:
>> On Sat, Aug 24, 2013 at 02:10:36AM +0100, Matthew Garrett wrote:
>>> On Fri, Aug 23, 2013 at 05:13:45PM -0700, Guenter Roeck wrote:
>>>
>>>> Did the group conclude that the idea of FDT augmenting ACPI is not feasible ?
>>>
>>> I think expressing FDT in ACPI is feasible, I'm just not sure it's
>>> desirable. We'd still end up with duplicate information and no mechanism
>>> for drivers to handle both.
>>>
>> Not sure I understand what you are saying. My understanding of "augment"
>> would be that there is ACPI information, and there is a separate FDT
>> (or an FDT overlay) providing additional information. There should be
>> no duplicate information in this model.
>
> What happens when you have an ACPI device that contains an interrupt in
> _CRS and contains a different interrupt in an embedded FDT block?
>

Question is: Does this work _today_ with any existing driver, where
one interrupt is served through ACPI and another as 'standard' Linux
interrupt ? If yes, it must be working, and using fdt to describe
the interrupt mapping for the non-ACPI interrupt should not make
a difference. If no, the problem does not really have anything
to do with fdt.

Guenter