ACPI: Disable Fixed_RTC event when installing RTC handler

The Fixed_RTC event should be disabled when installing RTC handler.
Only when RTC alarm is set will it be enabled again. If it is not
disabled, maybe some machines will be powered on automatically after
the system is shutdown even when the RTC alarm is not set.

http://bugzilla.kernel.org/show_bug.cgi?id=10010

Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/acpi/glue.c

@@ -272,6 +272,12 @@ static u32 rtc_handler(void *context)
 static inline void rtc_wake_setup(void)
 {
 	acpi_install_fixed_event_handler(ACPI_EVENT_RTC, rtc_handler, NULL);
+	/*
+	 * After the RTC handler is installed, the Fixed_RTC event should
+	 * be disabled. Only when the RTC alarm is set will it be enabled.
+	 */
+	acpi_clear_event(ACPI_EVENT_RTC);
+	acpi_disable_event(ACPI_EVENT_RTC, 0);
 }
 
 static void rtc_wake_on(struct device *dev)

drivers/acpi/sleep/proc.c

@@ -495,6 +495,12 @@ static int __init acpi_sleep_proc_init(void)
 		    acpi_root_dir, &acpi_system_alarm_fops);
 
 	acpi_install_fixed_event_handler(ACPI_EVENT_RTC, rtc_handler, NULL);
+	/*
+	 * Disable the RTC event after installing RTC handler.
+	 * Only when RTC alarm is set will it be enabled.
+	 */
+	acpi_clear_event(ACPI_EVENT_RTC);
+	acpi_disable_event(ACPI_EVENT_RTC, 0);
 #endif				/* HAVE_ACPI_LEGACY_ALARM */
 
 	/* 'wakeup device' [R/W] */