[RFC][PATCH] ACPI / ACPICA: Always use the same lock for GPE locking

[RFC][PATCH] ACPI / ACPICA: Always use the same lock for GPE locking

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rjw@sisk.pl>

The GPE locking is now inconsistent, because acpi_set_gpe(),
acpi_enable_gpe() and acpi_disable_gpe() use acpi_gbl_gpe_lock for
this purpose, while acpi_clear_gpe() and acpi_get_gpe_status() use
the ACPI_MTX_EVENTS mutex instead (the mutex is only acquired if
they are not executed in interrupt context).  Fix this by changing
acpi_clear_gpe() and acpi_get_gpe_status() so that they acquire
acpi_gbl_gpe_lock too.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reported-by: Robert Moore <robert.moore@intel.com>
---
 drivers/acpi/acpica/evxfevnt.c |   28 ++++++----------------------
 1 file changed, 6 insertions(+), 22 deletions(-)

Index: linux-2.6/drivers/acpi/acpica/evxfevnt.c
===================================================================
--- linux-2.6.orig/drivers/acpi/acpica/evxfevnt.c
+++ linux-2.6/drivers/acpi/acpica/evxfevnt.c
@@ -476,19 +476,13 @@ ACPI_EXPORT_SYMBOL(acpi_clear_event)
  ******************************************************************************/
 acpi_status acpi_clear_gpe(acpi_handle gpe_device, u32 gpe_number, u32 flags)
 {
+	acpi_cpu_flags cpu_flags;
 	acpi_status status = AE_OK;
 	struct acpi_gpe_event_info *gpe_event_info;
 
 	ACPI_FUNCTION_TRACE(acpi_clear_gpe);
 
-	/* Use semaphore lock if not executing at interrupt level */
-
-	if (flags & ACPI_NOT_ISR) {
-		status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
-		if (ACPI_FAILURE(status)) {
-			return_ACPI_STATUS(status);
-		}
-	}
+	cpu_flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
 
 	/* Ensure that we have a valid GPE number */
 
@@ -501,9 +495,7 @@ acpi_status acpi_clear_gpe(acpi_handle g
 	status = acpi_hw_clear_gpe(gpe_event_info);
 
       unlock_and_exit:
-	if (flags & ACPI_NOT_ISR) {
-		(void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
-	}
+	acpi_os_release_lock(acpi_gbl_gpe_lock, cpu_flags);
 	return_ACPI_STATUS(status);
 }
 
@@ -584,19 +576,13 @@ acpi_status
 acpi_get_gpe_status(acpi_handle gpe_device,
 		    u32 gpe_number, u32 flags, acpi_event_status * event_status)
 {
+	acpi_cpu_flags cpu_flags;
 	acpi_status status = AE_OK;
 	struct acpi_gpe_event_info *gpe_event_info;
 
 	ACPI_FUNCTION_TRACE(acpi_get_gpe_status);
 
-	/* Use semaphore lock if not executing at interrupt level */
-
-	if (flags & ACPI_NOT_ISR) {
-		status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
-		if (ACPI_FAILURE(status)) {
-			return_ACPI_STATUS(status);
-		}
-	}
+	cpu_flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
 
 	/* Ensure that we have a valid GPE number */
 
@@ -614,9 +600,7 @@ acpi_get_gpe_status(acpi_handle gpe_devi
 		*event_status |= ACPI_EVENT_FLAG_HANDLE;
 
       unlock_and_exit:
-	if (flags & ACPI_NOT_ISR) {
-		(void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
-	}
+	acpi_os_release_lock(acpi_gbl_gpe_lock, cpu_flags);
 	return_ACPI_STATUS(status);
 }