From: Bob Moore <robert.moore@xxxxxxxxx> 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.html Reported-by: Valdis Kletnieks <valdis.kletnieks@xxxxxx> Reported-by: Sabrina Dubroka <sd@xxxxxxxxxxxxxxx> Signed-off-by: Bob Moore <robert.moore@xxxxxxxxx> Signed-off-by: Lv Zheng <lv.zheng@xxxxxxxxx> --- drivers/acpi/acpica/acobject.h | 3 ++- drivers/acpi/acpica/dsmethod.c | 24 +++++++++++++++++++----- 2 files changed, 21 insertions(+), 6 deletions(-) diff --git a/drivers/acpi/acpica/acobject.h b/drivers/acpi/acpica/acobject.h index 1a4d618..22fb644 100644 --- a/drivers/acpi/acpica/acobject.h +++ b/drivers/acpi/acpica/acobject.h @@ -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 */ /****************************************************************************** * diff --git a/drivers/acpi/acpica/dsmethod.c b/drivers/acpi/acpica/dsmethod.c index 73764c7..3c7f737 100644 --- a/drivers/acpi/acpica/dsmethod.c +++ b/drivers/acpi/acpica/dsmethod.c @@ -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", @@ -349,13 +356,19 @@ 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.mutex->mutex.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)", acpi_ut_get_node_name(method_node), @@ -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; } -- 1.7.10 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
