[PATCH] ACPI / PM: Do not disable wakeup GPEs that have not been enabled

["Rafael J. Wysocki" <rjw@rjwysocki.net>]

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

In some cases acpi_device_wakeup() may be called to ensure wakeup
power to be off for a given device even though that device's wakeup
GPE has not been enabled so far.  It calls acpi_disable_gpe() on a
GPE that's not enabled and this causes ACPICA to return the AE_LIMIT
status code from that call which then is reported as an error by the
ACPICA's debug facilities (if enabled).  This may lead to a fair
amount of confusion, so introduce a new ACPI device wakeup flag
to store the wakeup GPE status and avoid disabling wakeup GPEs
that have not been enabled.

Reported-and-tested-by: Venkat Raghavulu <venkat.raghavulu@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/acpi/device_pm.c |   12 ++++++++++--
 include/acpi/acpi_bus.h  |    1 +
 2 files changed, 11 insertions(+), 2 deletions(-)

Index: linux-pm/include/acpi/acpi_bus.h
===================================================================
--- linux-pm.orig/include/acpi/acpi_bus.h
+++ linux-pm/include/acpi/acpi_bus.h
@@ -313,6 +313,7 @@ struct acpi_device_wakeup_flags {
 	u8 valid:1;		/* Can successfully enable wakeup? */
 	u8 run_wake:1;		/* Run-Wake GPE devices */
 	u8 notifier_present:1;  /* Wake-up notify handler has been installed */
+	u8 enabled:1;		/* Enabled for wakeup */
 };
 
 struct acpi_device_wakeup_context {
Index: linux-pm/drivers/acpi/device_pm.c
===================================================================
--- linux-pm.orig/drivers/acpi/device_pm.c
+++ linux-pm/drivers/acpi/device_pm.c
@@ -680,13 +680,21 @@ static int acpi_device_wakeup(struct acp
 		if (error)
 			return error;
 
+		if (adev->wakeup.flags.enabled)
+			return 0;
+
 		res = acpi_enable_gpe(wakeup->gpe_device, wakeup->gpe_number);
-		if (ACPI_FAILURE(res)) {
+		if (ACPI_SUCCESS(res)) {
+			adev->wakeup.flags.enabled = 1;
+		} else {
 			acpi_disable_wakeup_device_power(adev);
 			return -EIO;
 		}
 	} else {
-		acpi_disable_gpe(wakeup->gpe_device, wakeup->gpe_number);
+		if (adev->wakeup.flags.enabled) {
+			acpi_disable_gpe(wakeup->gpe_device, wakeup->gpe_number);
+			adev->wakeup.flags.enabled = 0;
+		}
 		acpi_disable_wakeup_device_power(adev);
 	}
 	return 0;