arm_cpuidle_suspend() may return -EOPNOTSUPP, or any value returned
by the cpu_ops/cpuidle_ops suspend call. arm_enter_idle_state() doesn't
update 'ret' with this value, meaning we always signal success to
cpuidle_enter_state(), causing it to update the usage counters as if we
succeeded.
Fixes: 191de17aa3 ("ARM64: cpuidle: Replace cpu_suspend by the common ARM/ARM64 function")
Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: 4.1+ <stable@vger.kernel.org> # 4.1+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
If the cpuidle init cpu operation returns -ENXIO, therefore reporting HW
failure or misconfiguration, the CPUidle driver skips the respective
cpuidle device initialization because the associated platform back-end HW
is not operational.
That prevents the system to crash and allows to handle the error gracefully.
For example, on Qcom's platform, each core has a SPM. The device associated
with this SPM is initialized before the cpuidle framework. If there is an error
in the initialization (eg. error in the DT), the system continues to boot but
in degraded mode as some SPM may not be correctly initialized.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
