From 4c0a59e1123f90b773d46942a6d505b3cb5bd406 Mon Sep 17 00:00:00 2001 From: Amit Kucheria Date: Tue, 21 May 2019 15:05:12 +0530 Subject: [PATCH] Documentation: arm: Link idle-states binding to "enable-method" property The "enable-method" property for cpu nodes needs to be "psci" for CPU idle management to be setup correctly. Add a note to the binding documentation to this effect to make it obvious. Signed-off-by: Amit Kucheria Acked-by: Sudeep Holla Signed-off-by: Rob Herring --- .../devicetree/bindings/arm/idle-states.txt | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/Documentation/devicetree/bindings/arm/idle-states.txt b/Documentation/devicetree/bindings/arm/idle-states.txt index 45730ba60af5..3bdbe675b9e6 100644 --- a/Documentation/devicetree/bindings/arm/idle-states.txt +++ b/Documentation/devicetree/bindings/arm/idle-states.txt @@ -241,9 +241,13 @@ processor idle states, defined as device tree nodes, are listed. - "psci" # On ARM 32-bit systems this property is optional -The nodes describing the idle states (state) can only be defined within the -idle-states node, any other configuration is considered invalid and therefore -must be ignored. +This assumes that the "enable-method" property is set to "psci" in the cpu +node[6] that is responsible for setting up CPU idle management in the OS +implementation. + +The nodes describing the idle states (state) can only be defined +within the idle-states node, any other configuration is considered invalid +and therefore must be ignored. =========================================== 4 - state node @@ -697,3 +701,6 @@ cpus { [5] Devicetree Specification https://www.devicetree.org/specifications/ + +[6] ARM Linux Kernel documentation - Booting AArch64 Linux + Documentation/arm64/booting.txt