ACPI: Disable _GTS and _BFS support by default

Executing BIOS code paths not exercised by Windows
tends to get Linux into trouble.

However, if a system does benefit from _GTS or _BFS,
acpi.gts=1 an acpi.bfs=1 are now available to enable them.

http://bugzilla.kernel.org/show_bug.cgi?id=13041

Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 26 insertions, 17 deletions

diff --git a/drivers/acpi/acpica/hwsleep.c b/drivers/acpi/acpica/hwsleep.c
index baa5fc05e124..db307a356f08 100644
--- a/drivers/acpi/acpica/hwsleep.c
+++ b/drivers/acpi/acpica/hwsleep.c
@@ -211,6 +211,12 @@ acpi_status acpi_enter_sleep_state_prep(u8 sleep_state)
 
 ACPI_EXPORT_SYMBOL(acpi_enter_sleep_state_prep)
 
+static unsigned int gts, bfs;
+module_param(gts, uint, 0644);
+module_param(bfs, uint, 0644);
+MODULE_PARM_DESC(gts, "Enable evaluation of _GTS on suspend.");
+MODULE_PARM_DESC(bfs, "Enable evaluation of _BFS on resume".);
+
 /*******************************************************************************
  *
  * FUNCTION:    acpi_enter_sleep_state
@@ -278,16 +284,18 @@ acpi_status asmlinkage acpi_enter_sleep_state(u8 sleep_state)
 		return_ACPI_STATUS(status);
 	}
 
-	/* Execute the _GTS method */
+	if (gts) {
+		/* Execute the _GTS method */
 
-	arg_list.count = 1;
-	arg_list.pointer = &arg;
-	arg.type = ACPI_TYPE_INTEGER;
-	arg.integer.value = sleep_state;
+		arg_list.count = 1;
+		arg_list.pointer = &arg;
+		arg.type = ACPI_TYPE_INTEGER;
+		arg.integer.value = sleep_state;
 
-	status = acpi_evaluate_object(NULL, METHOD_NAME__GTS, &arg_list, NULL);
-	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
-		return_ACPI_STATUS(status);
+		status = acpi_evaluate_object(NULL, METHOD_NAME__GTS, &arg_list, NULL);
+		if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
+			return_ACPI_STATUS(status);
+		}
 	}
 
 	/* Get current value of PM1A control */
@@ -513,18 +521,19 @@ acpi_status acpi_leave_sleep_state_prep(u8 sleep_state)
 		}
 	}
 
-	/* Execute the _BFS method */
+	if (bfs) {
+		/* Execute the _BFS method */
 
-	arg_list.count = 1;
-	arg_list.pointer = &arg;
-	arg.type = ACPI_TYPE_INTEGER;
-	arg.integer.value = sleep_state;
+		arg_list.count = 1;
+		arg_list.pointer = &arg;
+		arg.type = ACPI_TYPE_INTEGER;
+		arg.integer.value = sleep_state;
 
-	status = acpi_evaluate_object(NULL, METHOD_NAME__BFS, &arg_list, NULL);
-	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
-		ACPI_EXCEPTION((AE_INFO, status, "During Method _BFS"));
+		status = acpi_evaluate_object(NULL, METHOD_NAME__BFS, &arg_list, NULL);
+		if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
+			ACPI_EXCEPTION((AE_INFO, status, "During Method _BFS"));
+		}
 	}
-
 	return_ACPI_STATUS(status);
 }