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Commit 9f9adecd authored by Len Brown's avatar Len Brown
Browse files

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: default avatarLen Brown <len.brown@intel.com>
Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
parent da8cadb3

arch/x86/kernel/apm_32.c

+3 −7
Original line number Diff line number Diff line
@@ -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);

drivers/acpi/bus.c

+2 −5
Original line number Diff line number Diff line
@@ -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();

include/linux/pm.h

+9 −0
Original line number Diff line number Diff line
@@ -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 */

include/linux/pm_legacy.h

+0 −6
Original line number Diff line number Diff line
@@ -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)

kernel/power/main.c

+3 −0
Original line number Diff line number Diff line
@@ -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 */