ACPICA: Fix issues/fault with automatic "serialized" method support

History: This support changes a method to "serialized" on the fly if the
method generates an AE_ALREADY_EXISTS error, indicating the possibility
that it cannot handle reentrancy.

This fix repairs a couple of issues seen in the field, especially on
machines with many cores.

1) Delete method children only upon the exit of the last thread, so
as to not delete objects out from under running threads.

2) Set the "serialized" bit for the method only upon the exit of the
last thread, so as to not cause deadlock when running threads attempt
to exit.

3) Cleanup the use of the AML "MethodFlags" and internal method flags
so that there is no longer any confustion between the two.

Reported-by: Dana Myers <dana.myers@oracle.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/drivers/acpi/acpica/excreate.c b/drivers/acpi/acpica/excreate.c
index 3c61b48c73f5..ffac8c7e54c5 100644
--- a/drivers/acpi/acpica/excreate.c
+++ b/drivers/acpi/acpica/excreate.c
@@ -482,13 +482,11 @@ acpi_ex_create_method(u8 * aml_start,
         obj_desc->method.aml_length = aml_length;
 
         /*
-         * Disassemble the method flags. Split off the Arg Count
-         * for efficiency
+         * Disassemble the method flags. Split off the arg_count, Serialized
+         * flag, and sync_level for efficiency.
          */
         method_flags = (u8) operand[1]->integer.value;
 
-        obj_desc->method.method_flags =
-            (u8) (method_flags & ~AML_METHOD_ARG_COUNT);
         obj_desc->method.param_count =
             (u8) (method_flags & AML_METHOD_ARG_COUNT);
 
@@ -497,6 +495,8 @@ acpi_ex_create_method(u8 * aml_start,
          * created for this method when it is parsed.
          */
         if (method_flags & AML_METHOD_SERIALIZED) {
+                obj_desc->method.info_flags = ACPI_METHOD_SERIALIZED;
+
                 /*
                  * ACPI 1.0: sync_level = 0
                  * ACPI 2.0: sync_level = sync_level in method declaration