On Tue, May 22, 2018 at 03:29:25PM +0200, Geert Uytterhoeven wrote:
> According to Documentation/devicetree/bindings/arm/cpus.txt, the
> "enable-method" property should be a property of the individual CPU
> nodes, not of the parent "cpus" node. However, on R-Car M2-W (and on
> several other arm32 SoCs), the property is tied to the "cpus" node
> instead.
>
> Secondary CPU bringup and CPU hot (un)plug work regardless, as
> arm_dt_init_cpu_maps() falls back to looking in the "cpus" node.
>
> The cpuidle code does not have such a fallback, so it does not detect
> the enable-method. Note that cpuidle does not support the
> "renesas,apmu" enable-method yet, so for now this does not make any
> difference.
Is the implication that if we keep the current binding for cpu nodes
then at some point we will need to update the cpuidle binding?
>
> Signed-off-by: Geert Uytterhoeven <geert+rene...@glider.be>
> ---
> Arm64 and powerpc do not have such a fallback, but SH has, like arm32.
>
> This is marked RFC, as the alternative is to update the DT bindings to
> keep the status quo.
> ---
> arch/arm/boot/dts/r8a7791.dtsi | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm/boot/dts/r8a7791.dtsi b/arch/arm/boot/dts/r8a7791.dtsi
> index d568bd22d6cbd855..b214cb8f52e47109 100644
> --- a/arch/arm/boot/dts/r8a7791.dtsi
> +++ b/arch/arm/boot/dts/r8a7791.dtsi
> @@ -71,7 +71,6 @@
> cpus {
> #address-cells = <1>;
> #size-cells = <0>;
> - enable-method = "renesas,apmu";
>
> cpu0: cpu@0 {
> device_type = "cpu";
> @@ -83,6 +82,7 @@
> clock-latency = <300000>; /* 300 us */
> power-domains = <&sysc R8A7791_PD_CA15_CPU0>;
> next-level-cache = <&L2_CA15>;
> + enable-method = "renesas,apmu";
>
> /* kHz - uV - OPPs unknown yet */
> operating-points = <1500000 1000000>,
> @@ -101,6 +101,7 @@
> clocks = <&cpg CPG_CORE R8A7791_CLK_Z>;
> power-domains = <&sysc R8A7791_PD_CA15_CPU1>;
> next-level-cache = <&L2_CA15>;
> + enable-method = "renesas,apmu";
> };
>
> L2_CA15: cache-controller-0 {
> --
> 2.7.4
>
