Lockdep has identified this lock as a source of potential deadlock in
acpi. After reviewing the lock it's not clear what it's protecting. I
invite anyone who might know what the point of the lock is to describe it.
In the mean time I removed the lock completely which, so far, hasn't had
any ill effects on my test machines.
Cc: linux-acpi@xxxxxxxxxxxxxxx
Signed-off-by: Daniel Walker <dwalker@xxxxxxxxxx>
---
drivers/acpi/dispatcher/dsmethod.c | 5 --
drivers/acpi/events/evregion.c | 30 ---------
drivers/acpi/events/evxface.c | 5 --
drivers/acpi/executer/exsystem.c | 21 ------
drivers/acpi/executer/exutils.c | 127 ------------------------------------
drivers/acpi/namespace/nseval.c | 6 --
drivers/acpi/namespace/nsinit.c | 6 --
drivers/acpi/namespace/nsxfeval.c | 5 +-
8 files changed, 1 insertions(+), 204 deletions(-)
diff --git a/drivers/acpi/dispatcher/dsmethod.c b/drivers/acpi/dispatcher/dsmethod.c
index a3cf3d4..0b8af17 100644
--- a/drivers/acpi/dispatcher/dsmethod.c
+++ b/drivers/acpi/dispatcher/dsmethod.c
@@ -86,10 +86,6 @@ acpi_ds_method_error(acpi_status status, struct acpi_walk_state *walk_state)
if (acpi_gbl_exception_handler) {
- /* Exit the interpreter, allow handler to execute methods */
-
- acpi_ex_exit_interpreter();
-
/*
* Handler can map the exception code to anything it wants, including
* AE_OK, in which case the executing method will not be aborted.
@@ -101,7 +97,6 @@ acpi_ds_method_error(acpi_status status, struct acpi_walk_state *walk_state)
walk_state->opcode,
walk_state->aml_offset,
NULL);
- acpi_ex_enter_interpreter();
}
#ifdef ACPI_DISASSEMBLER
if (ACPI_FAILURE(status)) {
diff --git a/drivers/acpi/events/evregion.c b/drivers/acpi/events/evregion.c
index 236fbd1..4eb4c30 100644
--- a/drivers/acpi/events/evregion.c
+++ b/drivers/acpi/events/evregion.c
@@ -338,21 +338,10 @@ acpi_ev_address_space_dispatch(union acpi_operand_object *region_obj,
return_ACPI_STATUS(AE_NOT_EXIST);
}
- /*
- * We must exit the interpreter because the region
- * setup will potentially execute control methods
- * (e.g., _REG method for this region)
- */
- acpi_ex_exit_interpreter();
-
status = region_setup(region_obj, ACPI_REGION_ACTIVATE,
handler_desc->address_space.context,
®ion_context);
- /* Re-enter the interpreter */
-
- acpi_ex_enter_interpreter();
-
/* Check for failure of the Region Setup */
if (ACPI_FAILURE(status)) {
@@ -397,16 +386,6 @@ acpi_ev_address_space_dispatch(union acpi_operand_object *region_obj,
acpi_ut_get_region_name(region_obj->region.
space_id)));
- if (!(handler_desc->address_space.handler_flags &
- ACPI_ADDR_HANDLER_DEFAULT_INSTALLED)) {
- /*
- * For handlers other than the default (supplied) handlers, we must
- * exit the interpreter because the handler *might* block -- we don't
- * know what it will do, so we can't hold the lock on the intepreter.
- */
- acpi_ex_exit_interpreter();
- }
-
/* Call the handler */
status = handler(function, address, bit_width, value,
@@ -419,15 +398,6 @@ acpi_ev_address_space_dispatch(union acpi_operand_object *region_obj,
space_id)));
}
- if (!(handler_desc->address_space.handler_flags &
- ACPI_ADDR_HANDLER_DEFAULT_INSTALLED)) {
- /*
- * We just returned from a non-default handler, we must re-enter the
- * interpreter
- */
- acpi_ex_enter_interpreter();
- }
-
return_ACPI_STATUS(status);
}
diff --git a/drivers/acpi/events/evxface.c b/drivers/acpi/events/evxface.c
index 94a6efe..4e4bd7a 100644
--- a/drivers/acpi/events/evxface.c
+++ b/drivers/acpi/events/evxface.c
@@ -773,10 +773,6 @@ acpi_status acpi_acquire_global_lock(u16 timeout, u32 * handle)
return (AE_BAD_PARAMETER);
}
- /* Must lock interpreter to prevent race conditions */
-
- acpi_ex_enter_interpreter();
-
status = acpi_ex_acquire_mutex_object(timeout,
acpi_gbl_global_lock_mutex,
acpi_os_get_thread_id());
@@ -788,7 +784,6 @@ acpi_status acpi_acquire_global_lock(u16 timeout, u32 * handle)
*handle = acpi_gbl_global_lock_handle;
}
- acpi_ex_exit_interpreter();
return (status);
}
diff --git a/drivers/acpi/executer/exsystem.c b/drivers/acpi/executer/exsystem.c
index 1a4aa5e..6c82143 100644
--- a/drivers/acpi/executer/exsystem.c
+++ b/drivers/acpi/executer/exsystem.c
@@ -75,19 +75,12 @@ acpi_status acpi_ex_system_wait_semaphore(acpi_semaphore semaphore, u16 timeout)
if (status == AE_TIME) {
- /* We must wait, so unlock the interpreter */
-
- acpi_ex_relinquish_interpreter();
-
status = acpi_os_wait_semaphore(semaphore, 1, timeout);
ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
"*** Thread awake after blocking, %s\n",
acpi_format_exception(status)));
- /* Reacquire the interpreter */
-
- acpi_ex_reacquire_interpreter();
}
return_ACPI_STATUS(status);
@@ -122,19 +115,12 @@ acpi_ex_system_wait_mutex(acpi_mutex mutex, u16 timeout)
if (status == AE_TIME) {
- /* We must wait, so unlock the interpreter */
-
- acpi_ex_relinquish_interpreter();
-
status = acpi_os_acquire_mutex(mutex, timeout);
ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
"*** Thread awake after blocking, %s\n",
acpi_format_exception(status)));
- /* Reacquire the interpreter */
-
- acpi_ex_reacquire_interpreter();
}
return_ACPI_STATUS(status);
@@ -197,15 +183,8 @@ acpi_status acpi_ex_system_do_suspend(acpi_integer how_long)
{
ACPI_FUNCTION_ENTRY();
- /* Since this thread will sleep, we must release the interpreter */
-
- acpi_ex_relinquish_interpreter();
-
acpi_os_sleep(how_long);
- /* And now we must get the interpreter again */
-
- acpi_ex_reacquire_interpreter();
return (AE_OK);
}
diff --git a/drivers/acpi/executer/exutils.c b/drivers/acpi/executer/exutils.c
index 86c0388..815defd 100644
--- a/drivers/acpi/executer/exutils.c
+++ b/drivers/acpi/executer/exutils.c
@@ -71,133 +71,6 @@ static u32 acpi_ex_digits_needed(acpi_integer value, u32 base);
#ifndef ACPI_NO_METHOD_EXECUTION
/*******************************************************************************
*
- * FUNCTION: acpi_ex_enter_interpreter
- *
- * PARAMETERS: None
- *
- * RETURN: None
- *
- * DESCRIPTION: Enter the interpreter execution region. Failure to enter
- * the interpreter region is a fatal system error. Used in
- * conjunction with exit_interpreter.
- *
- ******************************************************************************/
-
-void acpi_ex_enter_interpreter(void)
-{
- acpi_status status;
-
- ACPI_FUNCTION_TRACE(ex_enter_interpreter);
-
- status = acpi_ut_acquire_mutex(ACPI_MTX_INTERPRETER);
- if (ACPI_FAILURE(status)) {
- ACPI_ERROR((AE_INFO,
- "Could not acquire AML Interpreter mutex"));
- }
-
- return_VOID;
-}
-
-/*******************************************************************************
- *
- * FUNCTION: acpi_ex_reacquire_interpreter
- *
- * PARAMETERS: None
- *
- * RETURN: None
- *
- * DESCRIPTION: Reacquire the interpreter execution region from within the
- * interpreter code. Failure to enter the interpreter region is a
- * fatal system error. Used in conjuction with
- * relinquish_interpreter
- *
- ******************************************************************************/
-
-void acpi_ex_reacquire_interpreter(void)
-{
- ACPI_FUNCTION_TRACE(ex_reacquire_interpreter);
-
- /*
- * If the global serialized flag is set, do not release the interpreter,
- * since it was not actually released by acpi_ex_relinquish_interpreter.
- * This forces the interpreter to be single threaded.
- */
- if (!acpi_gbl_all_methods_serialized) {
- acpi_ex_enter_interpreter();
- }
-
- return_VOID;
-}
-
-/*******************************************************************************
- *
- * FUNCTION: acpi_ex_exit_interpreter
- *
- * PARAMETERS: None
- *
- * RETURN: None
- *
- * DESCRIPTION: Exit the interpreter execution region. This is the top level
- * routine used to exit the interpreter when all processing has
- * been completed.
- *
- ******************************************************************************/
-
-void acpi_ex_exit_interpreter(void)
-{
- acpi_status status;
-
- ACPI_FUNCTION_TRACE(ex_exit_interpreter);
-
- status = acpi_ut_release_mutex(ACPI_MTX_INTERPRETER);
- if (ACPI_FAILURE(status)) {
- ACPI_ERROR((AE_INFO,
- "Could not release AML Interpreter mutex"));
- }
-
- return_VOID;
-}
-
-/*******************************************************************************
- *
- * FUNCTION: acpi_ex_relinquish_interpreter
- *
- * PARAMETERS: None
- *
- * RETURN: None
- *
- * DESCRIPTION: Exit the interpreter execution region, from within the
- * interpreter - before attempting an operation that will possibly
- * block the running thread.
- *
- * Cases where the interpreter is unlocked internally
- * 1) Method to be blocked on a Sleep() AML opcode
- * 2) Method to be blocked on an Acquire() AML opcode
- * 3) Method to be blocked on a Wait() AML opcode
- * 4) Method to be blocked to acquire the global lock
- * 5) Method to be blocked waiting to execute a serialized control method
- * that is currently executing
- * 6) About to invoke a user-installed opregion handler
- *
- ******************************************************************************/
-
-void acpi_ex_relinquish_interpreter(void)
-{
- ACPI_FUNCTION_TRACE(ex_relinquish_interpreter);
-
- /*
- * If the global serialized flag is set, do not release the interpreter.
- * This forces the interpreter to be single threaded.
- */
- if (!acpi_gbl_all_methods_serialized) {
- acpi_ex_exit_interpreter();
- }
-
- return_VOID;
-}
-
-/*******************************************************************************
- *
* FUNCTION: acpi_ex_truncate_for32bit_table
*
* PARAMETERS: obj_desc - Object to be truncated
diff --git a/drivers/acpi/namespace/nseval.c b/drivers/acpi/namespace/nseval.c
index d369164..2a98cc7 100644
--- a/drivers/acpi/namespace/nseval.c
+++ b/drivers/acpi/namespace/nseval.c
@@ -72,8 +72,6 @@ ACPI_MODULE_NAME("nseval")
* DESCRIPTION: Execute a control method or return the current value of an
* ACPI namespace object.
*
- * MUTEX: Locks interpreter
- *
******************************************************************************/
acpi_status acpi_ns_evaluate(struct acpi_evaluate_info * info)
{
@@ -189,9 +187,7 @@ acpi_status acpi_ns_evaluate(struct acpi_evaluate_info * info)
* Execute the method via the interpreter. The interpreter is locked
* here before calling into the AML parser
*/
- acpi_ex_enter_interpreter();
status = acpi_ps_execute_method(info);
- acpi_ex_exit_interpreter();
} else {
/*
* 2) Object is not a method, return its current value
@@ -213,13 +209,11 @@ acpi_status acpi_ns_evaluate(struct acpi_evaluate_info * info)
* resolution, we must lock it because we could access an opregion.
* The opregion access code assumes that the interpreter is locked.
*/
- acpi_ex_enter_interpreter();
/* Function has a strange interface */
status =
acpi_ex_resolve_node_to_value(&info->resolved_node, NULL);
- acpi_ex_exit_interpreter();
/*
* If acpi_ex_resolve_node_to_value() succeeded, the return value was placed
diff --git a/drivers/acpi/namespace/nsinit.c b/drivers/acpi/namespace/nsinit.c
index e4c5751..e6c93d4 100644
--- a/drivers/acpi/namespace/nsinit.c
+++ b/drivers/acpi/namespace/nsinit.c
@@ -270,11 +270,6 @@ acpi_ns_init_one_object(acpi_handle obj_handle,
}
/*
- * Must lock the interpreter before executing AML code
- */
- acpi_ex_enter_interpreter();
-
- /*
* Each of these types can contain executable AML code within the
* declaration.
*/
@@ -333,7 +328,6 @@ acpi_ns_init_one_object(acpi_handle obj_handle,
* We ignore errors from above, and always return OK, since we don't want
* to abort the walk on any single error.
*/
- acpi_ex_exit_interpreter();
return (AE_OK);
}
diff --git a/drivers/acpi/namespace/nsxfeval.c b/drivers/acpi/namespace/nsxfeval.c
index 38be586..64c63f0 100644
--- a/drivers/acpi/namespace/nsxfeval.c
+++ b/drivers/acpi/namespace/nsxfeval.c
@@ -322,15 +322,12 @@ acpi_evaluate_object(acpi_handle handle,
if (info->return_object) {
/*
- * Delete the internal return object. NOTE: Interpreter must be
- * locked to avoid race condition.
+ * Delete the internal return object.
*/
- acpi_ex_enter_interpreter();
/* Remove one reference on the return object (should delete it) */
acpi_ut_remove_reference(info->return_object);
- acpi_ex_exit_interpreter();
}
cleanup:
--
1.5.5.1.32.gba7d2
--
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