Hi Sergei,
On Thu, Aug 23, 2018 at 10:56 AM Sergei Shtylyov
<sergei.shtylyov@xxxxxxxxxxxxxxxxxx> wrote:
> On 8/23/2018 11:52 AM, Geert Uytterhoeven wrote:
> >>> According to R-Car Gen3 HW manual rev1.00, R-Car M3-N has two CAN
> >>> interfaces, similar to H3, M3-W and other SoCs from the same family.
> >>>
> >>> Add CAN placeholder nodes to avoid below DTC errors:
> >>> Error: arch/arm64/boot/dts/renesas/ulcb-kf.dtsi:19.1-6 Label or path can0 not found
> >>> Error: arch/arm64/boot/dts/renesas/ulcb-kf.dtsi:25.1-6 Label or path can1 not found
> >>>
> >>> These errors occur *after* the addition of r8a77965-m3nulcb-kf.dts.
> >>> Fix them beforehand.
> >>>
> >>> CAN support is inspired from below commits:
> >>> - v4.7 commit 308b7e4ba62e ("arm64: dts: r8a7795: Add CAN support")
> >>> - v4.11 commit 909c16252415 ("arm64: dts: r8a7796: Add CAN support")
> >>> - v4.12 commit bec0948e810f ("arm64: dts: r8a7796: Add reset control properties")
> >>>
> >>> Signed-off-by: Eugeniu Rosca <erosca@xxxxxxxxxxxxxx>
> >>> --- a/arch/arm64/boot/dts/renesas/r8a77965.dtsi
> >>> +++ b/arch/arm64/boot/dts/renesas/r8a77965.dtsi
> >>> @@ -656,6 +656,22 @@
> >>> status = "disabled";
> >>> };
> >>>
> >>> + can0: can@e6c30000 {
> >>> + compatible = "renesas,can-r8a77965",
> >>> + "renesas,rcar-gen3-can";
> >>> + reg = <0 0xe6c30000 0 0x1000>;
> >>> + /* placeholder */
> >>> + status = "disabled";
> >>> + };
> >>
> >> This is probably more detail than is needed for a placeholder, but it
> >> looks correct so I think this is fine.
> >
> > Indeed. Adding the "compatible" properties means they're no longer
> > placeholders, and will be probed by the driver, possibly leading to
> > undefined behavior.
>
> I don't think the disabled device nodes are actually probed.
They will be by ulcb-kf.dtsi, after the addition of
r8a77965-m3nulcb-kf.dts, cfr.
the errors and rationale documented in the commit message.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
