There is a seemingly useless check in drivers/acpi/osl.c added by
commit
bc73675 (ACPI: fixes a false alarm from lockdep), which really
is necessary to avoid false positive lockdep complaints. Document
this and rearrange the code related to it so that it makes fewer
checks.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
* having a static work_struct.
*/
* having a static work_struct.
*/
- dpc = kmalloc(sizeof(struct acpi_os_dpc), GFP_ATOMIC);
+ dpc = kzalloc(sizeof(struct acpi_os_dpc), GFP_ATOMIC);
if (!dpc)
return AE_NO_MEMORY;
if (!dpc)
return AE_NO_MEMORY;
* because the hotplug code may call driver .remove() functions,
* which invoke flush_scheduled_work/acpi_os_wait_events_complete
* to flush these workqueues.
* because the hotplug code may call driver .remove() functions,
* which invoke flush_scheduled_work/acpi_os_wait_events_complete
* to flush these workqueues.
+ *
+ * To prevent lockdep from complaining unnecessarily, make sure that
+ * there is a different static lockdep key for each workqueue by using
+ * INIT_WORK() for each of them separately.
- queue = hp ? kacpi_hotplug_wq :
- (type == OSL_NOTIFY_HANDLER ? kacpi_notify_wq : kacpid_wq);
- dpc->wait = hp ? 1 : 0;
-
- if (queue == kacpi_hotplug_wq)
+ if (hp) {
+ queue = kacpi_hotplug_wq;
+ dpc->wait = 1;
INIT_WORK(&dpc->work, acpi_os_execute_deferred);
INIT_WORK(&dpc->work, acpi_os_execute_deferred);
- else if (queue == kacpi_notify_wq)
+ } else if (type == OSL_NOTIFY_HANDLER) {
+ queue = kacpi_notify_wq;
INIT_WORK(&dpc->work, acpi_os_execute_deferred);
INIT_WORK(&dpc->work, acpi_os_execute_deferred);
+ } else {
+ queue = kacpid_wq;
INIT_WORK(&dpc->work, acpi_os_execute_deferred);
INIT_WORK(&dpc->work, acpi_os_execute_deferred);
/*
* On some machines, a software-initiated SMI causes corruption unless
/*
* On some machines, a software-initiated SMI causes corruption unless