PM: ACPI and APM must not be enabled at the same time
ACPI and APM used "pm_active" to guarantee that
they would not be simultaneously active.
But pm_active was recently moved under CONFIG_PM_LEGACY,
so that without CONFIG_PM_LEGACY, pm_active became a NOP --
allowing ACPI and APM to both be simultaneously enabled.
This caused unpredictable results, including boot hangs.
Further, the code under CONFIG_PM_LEGACY is scheduled
for removal.
So replace pm_active with pm_flags.
pm_flags depends only on CONFIG_PM,
which is present for both CONFIG_APM and CONFIG_ACPI.
http://bugzilla.kernel.org/show_bug.cgi?id=9194
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
diff --git a/arch/x86/kernel/apm_32.c b/arch/x86/kernel/apm_32.c
index 17089a0..af045ca 100644
--- a/arch/x86/kernel/apm_32.c
+++ b/arch/x86/kernel/apm_32.c
@@ -2256,14 +2256,12 @@
apm_info.disabled = 1;
return -ENODEV;
}
- if (PM_IS_ACTIVE()) {
+ if (pm_flags & PM_ACPI) {
printk(KERN_NOTICE "apm: overridden by ACPI.\n");
apm_info.disabled = 1;
return -ENODEV;
}
-#ifdef CONFIG_PM_LEGACY
- pm_active = 1;
-#endif
+ pm_flags |= PM_APM;
/*
* Set up a segment that references the real mode segment 0x40
@@ -2366,9 +2364,7 @@
kthread_stop(kapmd_task);
kapmd_task = NULL;
}
-#ifdef CONFIG_PM_LEGACY
- pm_active = 0;
-#endif
+ pm_flags &= ~PM_APM;
}
module_init(apm_init);
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 49d432d..d7a115c 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -29,7 +29,6 @@
#include <linux/list.h>
#include <linux/sched.h>
#include <linux/pm.h>
-#include <linux/pm_legacy.h>
#include <linux/device.h>
#include <linux/proc_fs.h>
#ifdef CONFIG_X86
@@ -764,16 +763,14 @@
result = acpi_bus_init();
if (!result) {
-#ifdef CONFIG_PM_LEGACY
- if (!PM_IS_ACTIVE())
- pm_active = 1;
+ if (!(pm_flags & PM_APM))
+ pm_flags |= PM_ACPI;
else {
printk(KERN_INFO PREFIX
"APM is already active, exiting\n");
disable_acpi();
result = -ENODEV;
}
-#endif
} else
disable_acpi();
diff --git a/include/linux/pm.h b/include/linux/pm.h
index 09a309b..b78e029 100644
--- a/include/linux/pm.h
+++ b/include/linux/pm.h
@@ -246,6 +246,15 @@
device_set_wakeup_enable(dev,val); \
} while(0)
+/*
+ * 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
+
#endif /* __KERNEL__ */
#endif /* _LINUX_PM_H */
diff --git a/include/linux/pm_legacy.h b/include/linux/pm_legacy.h
index 514729a..446f4f4 100644
--- a/include/linux/pm_legacy.h
+++ b/include/linux/pm_legacy.h
@@ -4,10 +4,6 @@
#ifdef CONFIG_PM_LEGACY
-extern int pm_active;
-
-#define PM_IS_ACTIVE() (pm_active != 0)
-
/*
* Register a device with power management
*/
@@ -21,8 +17,6 @@
#else /* CONFIG_PM_LEGACY */
-#define PM_IS_ACTIVE() 0
-
static inline struct pm_dev *pm_register(pm_dev_t type,
unsigned long id,
pm_callback callback)
diff --git a/kernel/power/main.c b/kernel/power/main.c
index 3cdf95b..f71c950 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -28,6 +28,9 @@
DEFINE_MUTEX(pm_mutex);
+unsigned int pm_flags;
+EXPORT_SYMBOL(pm_flags);
+
#ifdef CONFIG_SUSPEND
/* This is just an arbitrary number */
diff --git a/kernel/power/pm.c b/kernel/power/pm.c
index c50d152..60c73fa 100644
--- a/kernel/power/pm.c
+++ b/kernel/power/pm.c
@@ -27,8 +27,6 @@
#include <linux/interrupt.h>
#include <linux/mutex.h>
-int pm_active;
-
/*
* Locking notes:
* pm_devs_lock can be a semaphore providing pm ops are not called
@@ -204,6 +202,4 @@
EXPORT_SYMBOL(pm_register);
EXPORT_SYMBOL(pm_send_all);
-EXPORT_SYMBOL(pm_active);
-