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 <amit.kucheria@xxxxxxxxxx>
Acked-by: Sudeep Holla <sudeep.holla@xxxxxxx>
---
.../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
--
2.17.1
