On Wed, Aug 6, 2014 at 4:50 PM, Tim Bird <tbird20d@xxxxxxxxx> wrote: > On Wed, Aug 6, 2014 at 1:12 PM, Brian Norris > <computersforpeace@xxxxxxxxx> wrote: >> On Wed, Aug 06, 2014 at 01:42:08PM -0500, Rob Herring wrote: >>> On Wed, Aug 6, 2014 at 11:54 AM, Brian Norris <computersforpeace@xxxxxxxxx> wrote: >>> > On Thu, Jul 31, 2014 at 11:00:01AM -0700, Florian Fainelli wrote: >>> > I think it is important that a device tree provide some flexibility on >>> > kernel versions. We only invented 'interrupts-extended' in Linux 3.13, >>> > so it's easy to have device trees that could work only on 3.13+. >>> > >>> > Typically, we might say that new features require new kernels, but this >>> > is a very basic piece of the DT infrastructure. In our case, we have >>> > hardware whose basic features can be supported by a single interrupt >>> > parent, and so we used the 'interrupts' property pre-3.13. But when we >>> > want to add some power management features, there's an additional >>> > interrupt parent. Under the current DT binding, we have to switch over >>> > to using 'interrupts-extended' exclusively, and thus we must have a >>> > completely new DTB for >=3.13, and this DTB no longer works with the old >>> > kernels. >>> >>> "Must have" to enable the new features? >> >> Yes. The new feature requires an additional interrupt parent, and so it >> requires interrupts-extended. > > Hold on there. What about interrupt-map? That was the traditional DT > feature for > supporting multi-parented interrupts. Why couldn't the feature have been added > using that instead of interrupts-extended? It could have, but interrupts-extended is much more simple to express for the simple case of a device's interrupts routed to more than one parent. > I know interrupts-extended is preferred, but has interrupt-map support been > removed from recent kernels? I'm a bit confused. They are all still supported. It's just a question of order of parsing if you have find both styles. Rob -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
