5.10-stable review patch. If anyone has any objections, please let me know.
------------------
From: Rafael J. Wysocki rafael.j.wysocki@intel.com
[ Upstream commit 7b1b7961170e4fcad488755e5ffaaaf9bd527e8f ]
Refuse to register a cpuidle device if the given CPU has a cpuidle device already and print a message regarding it.
Without this, an attempt to register a new cpuidle device without unregistering the existing one leads to the removal of the existing cpuidle device without removing its sysfs interface.
Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/cpuidle/cpuidle.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index 83af15f77f66f..1c1fa6ac9244a 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -576,8 +576,14 @@ static void __cpuidle_device_init(struct cpuidle_device *dev) static int __cpuidle_register_device(struct cpuidle_device *dev) { struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); + unsigned int cpu = dev->cpu; int i, ret;
+ if (per_cpu(cpuidle_devices, cpu)) { + pr_info("CPU%d: cpuidle device already registered\n", cpu); + return -EEXIST; + } + if (!try_module_get(drv->owner)) return -EINVAL;
@@ -589,7 +595,7 @@ static int __cpuidle_register_device(struct cpuidle_device *dev) dev->states_usage[i].disable |= CPUIDLE_STATE_DISABLED_BY_USER; }
- per_cpu(cpuidle_devices, dev->cpu) = dev; + per_cpu(cpuidle_devices, cpu) = dev; list_add(&dev->device_list, &cpuidle_detected_devices);
ret = cpuidle_coupled_register_device(dev);