The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 763f191af51f127cf8e69cd361f50bf6180768a5 Mon Sep 17 00:00:00 2001

From: Ulf Hansson ulf.hansson@linaro.org Date: Thu, 1 Nov 2018 13:22:38 +0100 Subject: [PATCH] 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 073557f433eb..df564d783216 100644 --- 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);