Commit 3ae45a27 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki

ACPI: Make seemingly useless check in osl.c more understandable

There is a seemingly useless check in drivers/acpi/osl.c added by
commit bc73675b (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
Signed-off-by: default avatarRafael J. Wysocki <>
Acked-by: default avatarYinghai Lu <>
parent c5b18e22
......@@ -932,7 +932,7 @@ static acpi_status __acpi_os_execute(acpi_execute_type type,
* 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;
......@@ -944,17 +944,22 @@ static acpi_status __acpi_os_execute(acpi_execute_type type,
* 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);
else if (queue == kacpi_notify_wq)
} else if (type == OSL_NOTIFY_HANDLER) {
queue = kacpi_notify_wq;
INIT_WORK(&dpc->work, acpi_os_execute_deferred);
} else {
queue = kacpid_wq;
INIT_WORK(&dpc->work, acpi_os_execute_deferred);
* On some machines, a software-initiated SMI causes corruption unless
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