Commit 4f2c346e authored by Stuart Hayes's avatar Stuart Hayes Committed by Greg Kroah-Hartman
Browse files

driver core: fix async device shutdown hang 



Modify device_shutdown() so that supplier devices do not wait for
consumer devices to be shut down first when the devlink is sync state
only, since the consumer is not dependent on the supplier in this case.

Without this change, a circular dependency could hang the system.

Fixes: 8064952c ("driver core: shut down devices asynchronously")
Signed-off-by: default avatarStuart Hayes <stuart.w.hayes@gmail.com>
Tested-by: default avatarLaurence Oberman <loberman@redhat.com>
Tested-by: default avatarNathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20240919043143.1194950-1-stuart.w.hayes@gmail.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 6a36d828

drivers/base/core.c

+9 −1
Original line number Diff line number Diff line
@@ -4898,8 +4898,16 @@ void device_shutdown(void) 


		idx = device_links_read_lock();

		list_for_each_entry_rcu(link, &dev->links.suppliers, c_node,

				device_links_read_lock_held())

				device_links_read_lock_held()) {

			/*

			 * sync_state_only suppliers don't need to wait,

			 * aren't reordered on devices_kset, so making them

			 * wait could result in a hang

			 */

			if (device_link_flag_is_sync_state_only(link->flags))

				continue;

			link->supplier->p->shutdown_after = cookie;

		}

		device_links_read_unlock(idx);

		put_device(dev);