On Fri, Mar 31, 2017 at 06:51:38PM +0200, Patrick Menschel wrote: > Hello Maxime, > > Am 27.03.2017 um 08:46 schrieb Maxime Ripard: > >> @@ -1582,6 +1587,14 @@ > >> #size-cells = <0>; > >> }; > >> > >> + can0: can@01c2bc00 { > >> + compatible = "allwinner,sun4i-a10-can"; > > > > Sorry for not spotting this earlier, but this would need an A20 > > compatible too, to deal with the case where it turns out not to be > > compatible. > > > > you can do something like this: > > compatible = "allwinner,sun7i-a20-can", "allwinner,sun4i-a10-can"; > > Adding "sun7i-a20-can" to the compatible list results in a checkpatch > warning, that the "driver" is not documented. > > WARNING: DT compatible string "allwinner,sun7i-a20-can" appears > un-documented -- check ./Documentation/devicetree/bindings/ > #27: FILE: arch/arm/boot/dts/sun7i-a20.dtsi:1586: > + compatible = "allwinner,sun7i-a20-can", > > Is it really OK to add a driver that doesn't exist yet? It's not what you are doing, what you're doing is adding an extra compatible that is not there yet. Since it doesn't exist, it will fallback on the second one, which does exist. So yes, it's ok to do so. Maxime -- Maxime Ripard, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com -- 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