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PM: ACPI and APM must not be enabled at the same time

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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>
This commit is contained in:
Len Brown 2007-12-13 17:38:03 -05:00
parent da8cadb31b
commit 9f9adecd2d
6 changed files with 17 additions and 22 deletions
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10
arch/x86/kernel/apm_32.c
View File

@ -2256,14 +2256,12 @@ static int __init apm_init(void)
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 @@ static void __exit apm_exit(void)
kthread_stop(kapmd_task);
kapmd_task = NULL;
}
#ifdef CONFIG_PM_LEGACY
pm_active = 0;
#endif
pm_flags &= ~PM_APM;
}
module_init(apm_init);

7
drivers/acpi/bus.c
View File

@ -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 @@ static int __init acpi_init(void)
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();

9
include/linux/pm.h
View File

@ -246,6 +246,15 @@ static inline int call_platform_enable_wakeup(struct device *dev, int is_on)
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 */

6
include/linux/pm_legacy.h
View File

@ -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 @@ int __deprecated pm_send_all(pm_request_t rqst, void *data);
#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)

3
kernel/power/main.c
View File

@ -28,6 +28,9 @@ BLOCKING_NOTIFIER_HEAD(pm_chain_head);
DEFINE_MUTEX(pm_mutex);
unsigned int pm_flags;
EXPORT_SYMBOL(pm_flags);
#ifdef CONFIG_SUSPEND
/* This is just an arbitrary number */

4
kernel/power/pm.c
View File

@ -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 @@ int pm_send_all(pm_request_t rqst, void *data)
EXPORT_SYMBOL(pm_register);
EXPORT_SYMBOL(pm_send_all);
EXPORT_SYMBOL(pm_active);