On Fri, 15 Nov 2013 09:34:21 +0100, Pantelis Antoniou <panto@xxxxxxxxxxxxxxxxxxxxxxx> wrote: > Hi Grant, > > On Nov 14, 2013, at 10:22 PM, Grant Likely wrote: > > > On Thu, 14 Nov 2013 11:01:35 +0100, Pantelis Antoniou <panto@xxxxxxxxxxxxxxxxxxxxxxx> wrote: > >> On Nov 14, 2013, at 2:31 AM, Grant Likely wrote: > >>> On Tue, 12 Nov 2013 10:30:37 +0100, Pantelis Antoniou <panto@xxxxxxxxxxxxxxxxxxxxxxx> wrote: > >>>> On Nov 11, 2013, at 7:42 PM, Grant Likely wrote: > >>>>> On Fri, 8 Nov 2013 17:06:09 +0200, Pantelis Antoniou <panto@xxxxxxxxxxxxxxxxxxxxxxx> wrote: > >>>> I'm of the opinion that 'platform_device' shouldn't exist at all btw :) > >>>> Most of it's functionality can pretty easily be subsumed by device proper > >>>> and the world would be a better place :) > >>> > >>> I'm fine for merging some/all of the platform_device fields into struct > >>> device. There are a few things, like resources, which would probably be > >>> useful to have common on all struct device variants. However, > >>> platform_device is far more about matching drivers to devices. Even if > >>> all of platform_device went into struct device, there would still need > >>> to be the platform_bus_type as the collection point for the device > >>> drivers. > >>> > >> > >> We don't really need the resources structures on OF. That information is > >> present in OF format, which we can use to generate transient resources for > >> usage with the standard kernel interfaces. > >> > >> BTW, last time I checked resource handling was broken on release. > >> There are a few patches I sent out fixing it but they were probably ignored. > > > > Please send them again. They probably got lost. > > > >>>>> Can overlays interact in bad ways? If overlay 1 is installed before > >>>>> overlay 2, what happens if overlay 1 is removed? > >>>>> > >>>> > >>>> Yes, they can. It is not something easily fixed; the proper way would > >>>> be to calculate overlay intersection points and refuse to unload. > >>> > >>> I think this is important. If it cannot be solved immediately, then the > >>> kernel should enforce overlays always get removed in the reverse order > >>> that they were added. There may be use-cases that don't like it, but it > >>> is safe. > >> > >> OK, that makes sense. > >> > >> We are not talking about a global overlay stack though, we're talking about > >> an overlay stack for overlays that overlap. > > > > I'm actually talking about a global overlay stack. Otherwise you've > > still got the ever-increasing-phandles problem again. > > > > A global overlay stack is easiest. Let's do that first. > > There are use cases for multiple overlay stacks though. Take for instance the > case where you have multiple plugin connectors. > > Each one can lead to creating a new platform device under ocp, but there is > no overlap. > > Of course stackable expansion boards work just fine with a global overlay stack :) Agreed. baby steps... g. -- 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
