From 9f9adecd2d0e4f88fa0e8cb06c6ec207748df70a Mon Sep 17 00:00:00 2001 From: Len Brown Date: Thu, 13 Dec 2007 17:38:03 -0500 Subject: [PATCH] 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 Signed-off-by: Rafael J. Wysocki --- arch/x86/kernel/apm_32.c | 10 +++------- drivers/acpi/bus.c | 7 ++----- include/linux/pm.h | 9 +++++++++ include/linux/pm_legacy.h | 6 ------ kernel/power/main.c | 3 +++ kernel/power/pm.c | 4 ---- 6 files changed, 17 insertions(+), 22 deletions(-) diff --git a/arch/x86/kernel/apm_32.c b/arch/x86/kernel/apm_32.c index 17089a041028..af045ca0f653 100644 --- a/arch/x86/kernel/apm_32.c +++ b/arch/x86/kernel/apm_32.c @@ -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); diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c index 49d432d0a12c..d7a115c362d1 100644 --- a/drivers/acpi/bus.c +++ b/drivers/acpi/bus.c @@ -29,7 +29,6 @@ #include #include #include -#include #include #include #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(); diff --git a/include/linux/pm.h b/include/linux/pm.h index 09a309b7b5d2..b78e0295adf4 100644 --- a/include/linux/pm.h +++ b/include/linux/pm.h @@ -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 */ diff --git a/include/linux/pm_legacy.h b/include/linux/pm_legacy.h index 514729a44688..446f4f42b952 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 @@ 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) diff --git a/kernel/power/main.c b/kernel/power/main.c index 3cdf95b1dc92..f71c9504a5c5 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -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 */ diff --git a/kernel/power/pm.c b/kernel/power/pm.c index c50d15266c10..60c73fa670d5 100644 --- a/kernel/power/pm.c +++ b/kernel/power/pm.c @@ -27,8 +27,6 @@ #include #include -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); - -- 2.30.2