ARM: cpuidle: Don't register the driver when back-end init returns -ENXIO

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>

diff --git a/drivers/cpuidle/cpuidle-arm.c b/drivers/cpuidle/cpuidle-arm.c
index 073557f433eb1be630a7f64b8cfc9930771eff2a..df564d78321617670b947eafe81aa76050db7e6f 100644 (file)
--- a/drivers/cpuidle/cpuidle-arm.c
+++ b/drivers/cpuidle/cpuidle-arm.c
@@ -103,13 +103,6 @@ static int __init arm_idle_init_cpu(int cpu)
                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 cpu)
        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);