[PATCH 4.19 152/205] ARM: cpuidle: Dont register the driver when back-end init returns -ENXIO

Greg Kroah-Hartman
2018-11-19T16:38:35Z

From: Ulf Hansson <ulf.hansson@linaro.org>

commit 763f191af51f127cf8e69cd361f50bf6180768a5 upstream.

There's no point to register the cpuidle driver for the current CPU, when
the initialization of the arch specific back-end data fails by returning
-ENXIO.

Instead, let's re-order the sequence to its original flow, by first trying
to initialize the back-end part and then act accordingly on the returned
error code. Additionally, let's print the error message, no matter of what
error code that was returned.

Fixes: a0d46a3dfdc3 (ARM: cpuidle: Register per cpuidle device)
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: 4.19+ <stable@vger.kernel.org> # v4.19+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/cpuidle/cpuidle-arm.c | 22 ++++++++++------------
1 file changed, 10 insertions(+), 12 deletions(-)

--- a/drivers/cpuidle/cpuidle-arm.c
+++ b/drivers/cpuidle/cpuidle-arm.c
@@ -103,13 +103,6 @@ static int __init arm_idle_init_cpu(int
goto out_kfree_drv;
}

- ret = cpuidle_register_driver(drv);
- if (ret) {
- if (ret != -EBUSY)
- pr_err("Failed to register cpuidle driver\n");
- goto out_kfree_drv;
- }
-
/*
* Call arch CPU operations in order to initialize
* idle states suspend back-end specific data
@@ -117,15 +110,20 @@ static int __init arm_idle_init_cpu(int
ret = arm_cpuidle_init(cpu);

/*
- * Skip the cpuidle device initialization if the reported
+ * Allow the initialization to continue for other CPUs, if the reported
* failure is a HW misconfiguration/breakage (-ENXIO).
*/
- if (ret == -ENXIO)
- return 0;
-
if (ret) {
pr_err("CPU %d failed to init idle CPU ops\n", cpu);
- goto out_unregister_drv;
+ ret = ret == -ENXIO ? 0 : ret;
+ goto out_kfree_drv;
+ }
+
+ ret = cpuidle_register_driver(drv);
+ if (ret) {
+ if (ret != -EBUSY)
+ pr_err("Failed to register cpuidle driver\n");
+ goto out_kfree_drv;
}

dev = kzalloc(sizeof(*dev), GFP_KERNEL);