PM: Drop pm_flags that is not necessary

The variable pm_flags is used to prevent APM from being enabled
along with ACPI, which would lead to problems.  However, acpi_init()
is always called before apm_init() and after acpi_init() has
returned, it is known whether or not ACPI will be used.  Namely, if
acpi_disabled is not set after acpi_init() has returned, this means
that ACPI is enabled.  Thus, it is sufficient to check acpi_disabled
in apm_init() to prevent APM from being enabled in parallel with
ACPI.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Len Brown <len.brown@intel.com>

5 files changed, 7 insertions, 48 deletions

diff --git a/arch/x86/kernel/apm_32.c b/arch/x86/kernel/apm_32.c
index 0e4f24c2a746..15f47f741983 100644
--- a/arch/x86/kernel/apm_32.c
+++ b/arch/x86/kernel/apm_32.c
@@ -227,6 +227,7 @@
 #include <linux/suspend.h>
 #include <linux/kthread.h>
 #include <linux/jiffies.h>
+#include <linux/acpi.h>
 
 #include <asm/system.h>
 #include <asm/uaccess.h>
@@ -2331,12 +2332,11 @@ static int __init apm_init(void)
                 apm_info.disabled = 1;
                 return -ENODEV;
         }
-        if (pm_flags & PM_ACPI) {
+        if (!acpi_disabled) {
                 printk(KERN_NOTICE "apm: overridden by ACPI.\n");
                 apm_info.disabled = 1;
                 return -ENODEV;
         }
-        pm_flags |= PM_APM;
 
         /*
          * Set up the long jump entry point to the APM BIOS, which is called
@@ -2428,7 +2428,6 @@ static void __exit apm_exit(void)
                 kthread_stop(kapmd_task);
                 kapmd_task = NULL;
         }
-        pm_flags &= ~PM_APM;
 }
 
 module_init(apm_init);
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 973b0709972c..9749980ca6ca 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -1007,8 +1007,7 @@ struct kobject *acpi_kobj;
 
 static int __init acpi_init(void)
 {
-        int result = 0;
-
+        int result;
 
         if (acpi_disabled) {
                 printk(KERN_INFO PREFIX "Interpreter disabled.\n");
@@ -1023,29 +1022,18 @@ static int __init acpi_init(void)
 
         init_acpi_device_notify();
         result = acpi_bus_init();
-
-        if (!result) {
-                pci_mmcfg_late_init();
-                if (pm_apm_enabled()) {
-                        printk(KERN_INFO PREFIX
-                               "APM is already active, exiting\n");
-                        disable_acpi();
-                        result = -ENODEV;
-                } else {
-                        pm_set_acpi_flag();
-                }
-        } else
+        if (result) {
                 disable_acpi();
-
-        if (acpi_disabled)
                 return result;
+        }
 
+        pci_mmcfg_late_init();
         acpi_scan_init();
         acpi_ec_init();
         acpi_debugfs_init();
         acpi_sleep_proc_init();
         acpi_wakeup_device_init();
-        return result;
+        return 0;
 }
 
 subsys_initcall(acpi_init);
diff --git a/include/linux/pm.h b/include/linux/pm.h
index 9279175a4557..1f79c98f1e56 100644
--- a/include/linux/pm.h
+++ b/include/linux/pm.h
@@ -565,15 +565,6 @@ enum dpm_order {
         DPM_ORDER_DEV_LAST,
 };
 
-/*
- * Global Power Management flags
- * Used to keep APM and ACPI from both being active
- */
-extern unsigned int     pm_flags;
-
-#define PM_APM  1
-#define PM_ACPI 2
-
 extern int pm_generic_suspend(struct device *dev);
 extern int pm_generic_resume(struct device *dev);
 extern int pm_generic_freeze(struct device *dev);
diff --git a/include/linux/suspend.h b/include/linux/suspend.h
index 5e364db8a56a..5a89e3612875 100644
--- a/include/linux/suspend.h
+++ b/include/linux/suspend.h
@@ -272,9 +272,6 @@ extern int unregister_pm_notifier(struct notifier_block *nb);
         register_pm_notifier(&fn##_nb);                 \
 }
 
-extern bool pm_apm_enabled(void);
-extern void pm_set_acpi_flag(void);
-
 /* drivers/base/power/wakeup.c */
 extern bool events_check_enabled;
 
@@ -295,9 +292,6 @@ static inline int unregister_pm_notifier(struct notifier_block *nb)
 
 #define pm_notifier(fn, pri)    do { (void)(fn); } while (0)
 
-static inline bool pm_apm_enabled(void) { return false; }
-static inline void pm_set_acpi_flag(void) {}
-
 static inline bool pm_wakeup_pending(void) { return false; }
 #endif /* !CONFIG_PM_SLEEP */
 
diff --git a/kernel/power/main.c b/kernel/power/main.c
index b5405af48ddb..8eaba5f27b10 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -19,19 +19,6 @@ DEFINE_MUTEX(pm_mutex);
 
 #ifdef CONFIG_PM_SLEEP
 
-unsigned int pm_flags;
-EXPORT_SYMBOL(pm_flags);
-
-bool pm_apm_enabled(void)
-{
-        return !!(pm_flags & PM_APM);
-}
-
-void pm_set_acpi_flag(void)
-{
-        pm_flags |= PM_ACPI;
-}
-
 /* Routines for PM-transition notifications */
 
 static BLOCKING_NOTIFIER_HEAD(pm_chain_head);