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>

1 files changed, 2 insertions, 5 deletions

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 <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();