Merge back cpuidle material for 5.10.

* pm-cpuidle:
  cpuidle: record state entry rejection statistics
  cpuidle: psci: Allow PM domain to be initialized even if no OSI mode
  firmware: psci: Extend psci_set_osi_mode() to allow reset to PC mode
  ACPI: processor: Print more information when acpi_processor_evaluate_cst() fails
  cpuidle: tegra: Correctly handle result of arm_cpuidle_simple_enter()

1 files changed, 9 insertions, 0 deletions

diff --git a/Documentation/admin-guide/pm/cpuidle.rst b/Documentation/admin-guide/pm/cpuidle.rst
index 6ebe163f9dfe..37940a0584ec 100644
--- a/Documentation/admin-guide/pm/cpuidle.rst
+++ b/Documentation/admin-guide/pm/cpuidle.rst
@@ -528,6 +528,10 @@ object corresponding to it, as follows:
 	Total number of times the hardware has been asked by the given CPU to
 	enter this idle state.
 
+``rejected``
+	Total number of times a request to enter this idle state on the given
+	CPU was rejected.
+
 The :file:`desc` and :file:`name` files both contain strings.  The difference
 between them is that the name is expected to be more concise, while the
 description may be longer and it may contain white space or special characters.
@@ -572,6 +576,11 @@ particular case.  For these reasons, the only reliable way to find out how
 much time has been spent by the hardware in different idle states supported by
 it is to use idle state residency counters in the hardware, if available.
 
+Generally, an interrupt received when trying to enter an idle state causes the
+idle state entry request to be rejected, in which case the ``CPUIdle`` driver
+may return an error code to indicate that this was the case. The :file:`usage`
+and :file:`rejected` files report the number of times the given idle state
+was entered successfully or rejected, respectively.
 
 .. _cpu-pm-qos: