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Revert "ACPI: processor: idle: Optimize ACPI idle driver registration" 

Revert commit 7a8c994cbb ("ACPI: processor: idle: Optimize ACPI idle
driver registration") because it is reported to introduce a cpuidle
regression leading to a kernel crash on a platform using the ACPI idle
driver.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reported-by: Borislav Petkov <bp@alien8.de>
Tested-by: Borislav Petkov (AMD) <bp@alien8.de>
Closes: https://lore.kernel.org/lkml/20251124200019.GIaSS5U9HhsWBotrQZ@fat_crate.local/
This commit is contained in:
Rafael J. Wysocki 2025-11-25 15:06:12 +01:00
parent 1a8b350182
commit 43ff36c4a5
3 changed files with 23 additions and 47 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
drivers/acpi/processor_driver.c
View File

@ -263,8 +263,6 @@ static int __init acpi_processor_driver_init(void)
if (result < 0)
return result;
acpi_processor_register_idle_driver();
result = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
"acpi/cpu-drv:online",
acpi_soft_cpu_online, NULL);
@ -303,7 +301,6 @@ static void __exit acpi_processor_driver_exit(void)
cpuhp_remove_state_nocalls(hp_online);
cpuhp_remove_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD);
acpi_processor_unregister_idle_driver();
driver_unregister(&acpi_processor_driver);
}

65
drivers/acpi/processor_idle.c
View File

@ -1357,48 +1357,7 @@ int acpi_processor_power_state_has_changed(struct acpi_processor *pr)
return 0;
}
void acpi_processor_register_idle_driver(void)
{
struct acpi_processor *pr;
int ret = -ENODEV;
int cpu;
/*
* Acpi idle driver is used by all possible CPUs.
* Install the idle handler by the processor power info of one in them.
* Note that we use previously set idle handler will be used on
* platforms that only support C1.
*/
for_each_cpu(cpu, (struct cpumask *)cpu_possible_mask) {
pr = per_cpu(processors, cpu);
if (!pr)
continue;
ret = acpi_processor_get_power_info(pr);
if (!ret) {
pr->flags.power_setup_done = 1;
acpi_processor_setup_cpuidle_states(pr);
break;
}
}
if (ret) {
pr_debug("No ACPI power information from any CPUs.\n");
return;
}
ret = cpuidle_register_driver(&acpi_idle_driver);
if (ret) {
pr_debug("register %s failed.\n", acpi_idle_driver.name);
return;
}
pr_debug("%s registered with cpuidle.\n", acpi_idle_driver.name);
}
void acpi_processor_unregister_idle_driver(void)
{
cpuidle_unregister_driver(&acpi_idle_driver);
}
static int acpi_processor_registered;
int acpi_processor_power_init(struct acpi_processor *pr)
{
@ -1413,7 +1372,22 @@ int acpi_processor_power_init(struct acpi_processor *pr)
if (!acpi_processor_get_power_info(pr))
pr->flags.power_setup_done = 1;
/*
* Install the idle handler if processor power management is supported.
* Note that we use previously set idle handler will be used on
* platforms that only support C1.
*/
if (pr->flags.power) {
/* Register acpi_idle_driver if not already registered */
if (!acpi_processor_registered) {
acpi_processor_setup_cpuidle_states(pr);
retval = cpuidle_register_driver(&acpi_idle_driver);
if (retval)
return retval;
pr_debug("%s registered with cpuidle\n",
acpi_idle_driver.name);
}
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (!dev)
return -ENOMEM;
@ -1426,11 +1400,14 @@ int acpi_processor_power_init(struct acpi_processor *pr)
*/
retval = cpuidle_register_device(dev);
if (retval) {
if (acpi_processor_registered == 0)
cpuidle_unregister_driver(&acpi_idle_driver);
per_cpu(acpi_cpuidle_device, pr->id) = NULL;
kfree(dev);
return retval;
}
acpi_processor_registered++;
}
return 0;
}
@ -1444,6 +1421,10 @@ int acpi_processor_power_exit(struct acpi_processor *pr)
if (pr->flags.power) {
cpuidle_unregister_device(dev);
acpi_processor_registered--;
if (acpi_processor_registered == 0)
cpuidle_unregister_driver(&acpi_idle_driver);
kfree(dev);
}

2
include/acpi/processor.h
View File

@ -423,8 +423,6 @@ int acpi_processor_power_init(struct acpi_processor *pr);
int acpi_processor_power_exit(struct acpi_processor *pr);
int acpi_processor_power_state_has_changed(struct acpi_processor *pr);
int acpi_processor_hotplug(struct acpi_processor *pr);
void acpi_processor_register_idle_driver(void);
void acpi_processor_unregister_idle_driver(void);
#else
static inline int acpi_processor_power_init(struct acpi_processor *pr)
{