From: Bob Moore <robert.moore@xxxxxxxxx>
The ACPI 4.0 specification has been changed to make the SyncLevel
for mutex objects more useful. When releasing a mutex, the
synclevel of the mutex must now be the same as the current sync
level. This makes more sense. This change updates the code to
match the spec.
Signed-off-by: Bob Moore <robert.moore@xxxxxxxxx>
Signed-off-by: Lin Ming <ming.m.lin@xxxxxxxxx>
Signed-off-by: Len Brown <len.brown@xxxxxxxxx>
---
drivers/acpi/acpica/exmutex.c | 15 +++++++++++----
1 files changed, 11 insertions(+), 4 deletions(-)
diff --git a/drivers/acpi/acpica/exmutex.c b/drivers/acpi/acpica/exmutex.c
index 77a592a..2f01142 100644
--- a/drivers/acpi/acpica/exmutex.c
+++ b/drivers/acpi/acpica/exmutex.c
@@ -402,10 +402,14 @@ acpi_ex_release_mutex(union acpi_operand_object *obj_desc,
}
/*
- * The sync level of the mutex must be less than or equal to the current
- * sync level
+ * The sync level of the mutex must be equal to the current sync level. In
+ * other words, the current level means that at least one mutex at that
+ * level is currently being held. Attempting to release a mutex of a
+ * different level can only mean that the mutex ordering rule is being
+ * violated. This behavior is clarified in ACPI 4.0 specification.
*/
- if (obj_desc->mutex.sync_level > walk_state->thread->current_sync_level) {
+ if (obj_desc->mutex.sync_level !=
+ walk_state->thread->current_sync_level) {
ACPI_ERROR((AE_INFO,
"Cannot release Mutex [%4.4s], SyncLevel mismatch: mutex %d current %d",
acpi_ut_get_node_name(obj_desc->mutex.node),
@@ -423,10 +427,13 @@ acpi_ex_release_mutex(union acpi_operand_object *obj_desc,
walk_state->thread->acquired_mutex_list->mutex.original_sync_level;
status = acpi_ex_release_mutex_object(obj_desc);
+ if (ACPI_FAILURE(status)) {
+ return_ACPI_STATUS(status);
+ }
if (obj_desc->mutex.acquisition_depth == 0) {
- /* Restore the original sync_level */
+ /* Restore the previous sync_level */
walk_state->thread->current_sync_level = previous_sync_level;
}
--
1.6.0.6
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