ACPI: processor: Reorder acpi_processor_driver_init()

The cpufreq policy notifier in the ACPI processor driver may as
well be registered before the driver itself, which causes
acpi_processor_cpufreq_init to be true (unless the notifier
registration fails, which is unlikely at that point) when the
ACPI CPU thermal cooling devices are registered, so the
processor_get_max_state() result does not change while
acpi_processor_driver_init() is running.

Change the ordering in acpi_processor_driver_init() accordingly
to prevent the max_state value from remaining 0 permanently for all
ACPI CPU cooling devices due to setting acpi_processor_cpufreq_init
too late.  [Note that processor_get_max_state() may still return
different values at different times after this change, depending on
the cpufreq driver registration time, but that issue needs to be
addressed separately.]

Fixes: a365105c685c("thermal: sysfs: Reuse cdev->max_state")
Reported-by: Wang, Quanxian <quanxian.wang@intel.com>
Link: https://lore.kernel.org/linux-pm/53ec1f06f61c984100868926f282647e57ecfb2d.camel@intel.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Reviewed-by: Zhang Rui <rui.zhang@intel.com>

diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c
index 1278969..4bd16b3 100644 (file)
--- a/drivers/acpi/processor_driver.c
+++ b/drivers/acpi/processor_driver.c
@@ -263,6 +263,12 @@ static int __init acpi_processor_driver_init(void)
        if (acpi_disabled)
                return 0;
 
+       if (!cpufreq_register_notifier(&acpi_processor_notifier_block,
+                                      CPUFREQ_POLICY_NOTIFIER)) {
+               acpi_processor_cpufreq_init = true;
+               acpi_processor_ignore_ppc_init();
+       }
+
        result = driver_register(&acpi_processor_driver);
        if (result < 0)
                return result;
@@ -276,12 +282,6 @@ static int __init acpi_processor_driver_init(void)
        cpuhp_setup_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD, "acpi/cpu-drv:dead",
                                  NULL, acpi_soft_cpu_dead);
 
-       if (!cpufreq_register_notifier(&acpi_processor_notifier_block,
-                                      CPUFREQ_POLICY_NOTIFIER)) {
-               acpi_processor_cpufreq_init = true;
-               acpi_processor_ignore_ppc_init();
-       }
-
        acpi_processor_throttling_init();
        return 0;
 err: