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

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
checks.

Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: default avatarYinghai Lu <yinghai@kernel.org>
parent c5b18e22

drivers/acpi/osl.c

+13 −8
Original line number Diff line number Diff line
@@ -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

	} 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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