On Mon, Dec 14, 2015 at 11:22:46AM +0100, Geert Uytterhoeven wrote: > On Sat, Dec 12, 2015 at 6:51 AM, David Gibson > <david@xxxxxxxxxxxxxxxxxxxxx> wrote: > > On Thu, Dec 10, 2015 at 12:43:24PM -0800, Brian Norris wrote: > >> On Mon, Dec 07, 2015 at 12:36:28PM +1100, David Gibson wrote: > >> > On Sat, Dec 05, 2015 at 10:33:30PM +0100, Michal Suchanek wrote: > >> > > On 5 December 2015 at 12:39, Jonas Gorski <jogo@xxxxxxxxxxx> wrote: > >> > > > On Sat, Dec 5, 2015 at 6:19 AM, Brian Norris > >> > > > <computersforpeace@xxxxxxxxx> wrote: > >> > > > >> > > >> + > >> > > >> +Examples: > >> > > >> + > >> > > >> +flash@0 { > >> > > >> + partitions { > >> > > >> + compatible = "google,fmap"; > >> > > >> + }; > >> > > >> +}; > >> > > > > >> > > > I wonder if this wouldn't be better served in a separate binding doc > >> > > > with its compatible name as the filename, like we do with > >> > > > driver^Whardware blocks, especially if we want to add more parsers. > >> > > > >> > > > >> > > I find that *very* counter productive for bindings that go to the same > >> > > node. You have a description of a node, and then suddenly there you > >> > > have another file with another description of the same node. Totally > >> > > awesome. > >> > > >> > I can't actually work out from that if you're agreeing with the > >> > original post or the first reply. > >> > >> Perhaps I'm biased, but I think he was agreeing with the first reply. > >> (Particularly, "I find that *very* counter productive" uses the word > >> "that" to refer to "separate binding doc[s]".) > >> > >> > > Also how do you plan to write partitioning schemes with parameters > >> > > like with non-zero offset of the partition table. > >> > >> If you are directing this question at me: I don't have a specific plan > >> for it. MTD parsers don't currently take external input for this; many > >> scan the whole device, but some might also have conventions built into > >> the parser itself too, so this just gets hooked based on "compatible". > >> But if the need arose, I would hope we could work out a common binding. > >> > >> > Presumably with properties in the patitions node. Not seeing the > >> > problem here. > >> > >> I believe Michal is bringing up the (important, IMO) point that if > >> distinct partition types are being described in the same node, then any > >> use of additional properties *must* be closely coordinated. We can't > >> have two parsers "foo" and "bar" defining conflicting uses of the same > >> property in the same node, like this: > >> > >> partitions { > >> compatible = "foo", "bar"; > >> property-baz = ...; // e.g., reg = <...>; > >> }; > >> > >> where if "foo" is not found, we fall back to "bar". But what if "foo" > >> and "bar" use "property-baz" differently? > > > > Ah.. that is an excellent point, and leads me to realise that using > > compatible in this way is wrong. The whole point of compatible is > > that the node is, well, compatible with *all* the things in the list, > > and therefore the things in the list are compatible with each other. > > > > Using it for a list of entirely different things to attempt in order > > is not correct. > > Isn't the idea behind a partition table that all partition information is > stored on the device in a well-known format, so you don't need additional > properties? I guess that's the idea, but I wouldn't like to count on it. And more importantly, it's still abusing the 'compatible' property. A node is supposed to be compatible with *everything* in 'compatible', not just one of the things listed there. > If the only property needed is the partition table offset, it can be encoded > in the unit-address, and the "reg" property: > > partitions { > > partition-table@xxxx { > reg = <0xxxx ...>; > ... > }; > > ... > }; Urgh.. and that's abusing the unit address. -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson
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