Commit d1825579 authored by Bob Moore's avatar Bob Moore Committed by Rafael J. Wysocki

ACPICA: Ignore sync_level for methods that have been auto-serialized.

Cannot use a sync_level for methods that have been serialized at load-time
or runtime because this may interfere with any existing use of sync_levels
within the ASL code. So, we simply ignore the sync_level for these methods,
thus preserving any existing sync_level priorities. Note, the use of
sync_levels is actually rather rare within BIOS ASL code.

References: http://www.spinics.net/lists/linux-acpi/msg49496.htmlReported-by: default avatarValdis Kletnieks <valdis.kletnieks@vt.edu>
Reported-by: default avatarSabrina Dubroka <sd@queasysnail.net>
Signed-off-by: default avatarBob Moore <robert.moore@intel.com>
Signed-off-by: default avatarLv Zheng <lv.zheng@intel.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 21bd7e61
......@@ -193,7 +193,8 @@ struct acpi_object_method {
#define ACPI_METHOD_INTERNAL_ONLY 0x02 /* Method is implemented internally (_OSI) */
#define ACPI_METHOD_SERIALIZED 0x04 /* Method is serialized */
#define ACPI_METHOD_SERIALIZED_PENDING 0x08 /* Method is to be marked serialized */
#define ACPI_METHOD_MODIFIED_NAMESPACE 0x10 /* Method modified the namespace */
#define ACPI_METHOD_IGNORE_SYNC_LEVEL 0x10 /* Method was auto-serialized at table load time */
#define ACPI_METHOD_MODIFIED_NAMESPACE 0x20 /* Method modified the namespace */
/******************************************************************************
*
......
......@@ -175,8 +175,15 @@ acpi_ds_detect_named_opcodes(struct acpi_walk_state *walk_state,
* At this point, we know we have a Named object opcode.
* Mark the method as serialized. Later code will create a mutex for
* this method to enforce serialization.
*
* Note, ACPI_METHOD_IGNORE_SYNC_LEVEL flag means that we will ignore the
* Sync Level mechanism for this method, even though it is now serialized.
* Otherwise, there can be conflicts with existing ASL code that actually
* uses sync levels.
*/
walk_state->method_desc->method.info_flags |= ACPI_METHOD_SERIALIZED;
walk_state->method_desc->method.sync_level = 0;
walk_state->method_desc->method.info_flags |=
(ACPI_METHOD_SERIALIZED | ACPI_METHOD_IGNORE_SYNC_LEVEL);
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Method serialized [%4.4s] %p - [%s] (%4.4X)\n",
......@@ -349,12 +356,18 @@ acpi_ds_begin_method_execution(struct acpi_namespace_node *method_node,
/*
* The current_sync_level (per-thread) must be less than or equal to
* the sync level of the method. This mechanism provides some
* deadlock prevention
* deadlock prevention.
*
* If the method was auto-serialized, we just ignore the sync level
* mechanism, because auto-serialization of methods can interfere
* with ASL code that actually uses sync levels.
*
* Top-level method invocation has no walk state at this point
*/
if (walk_state &&
(walk_state->thread->current_sync_level >
(!(obj_desc->method.
info_flags & ACPI_METHOD_IGNORE_SYNC_LEVEL))
&& (walk_state->thread->current_sync_level >
obj_desc->method.mutex->mutex.sync_level)) {
ACPI_ERROR((AE_INFO,
"Cannot acquire Mutex for method [%4.4s], current SyncLevel is too large (%u)",
......@@ -800,7 +813,8 @@ acpi_ds_terminate_control_method(union acpi_operand_object *method_desc,
method_desc->method.info_flags &=
~ACPI_METHOD_SERIALIZED_PENDING;
method_desc->method.info_flags |=
ACPI_METHOD_SERIALIZED;
(ACPI_METHOD_SERIALIZED |
ACPI_METHOD_IGNORE_SYNC_LEVEL);
method_desc->method.sync_level = 0;
}
......
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