Commit 1689cac5 authored by Vivek Gautam's avatar Vivek Gautam Committed by Rafael J. Wysocki
Browse files

driver core: Add flag to autoremove device link on supplier unbind 



Add a flag to autoremove the device links on supplier driver
unbind. This obviates the need to explicitly delete the link
in the remove path.
We remove these links only when the supplier's link to its
consumers has gone to DL_STATE_SUPPLIER_UNBIND state.

Signed-off-by: default avatarVivek Gautam <vivek.gautam@codeaurora.org>
Suggested-by: default avatarLukas Wunner <lukas@wunner.de>
Reviewed-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent e88728f4

Documentation/driver-api/device_link.rst

+4 −0
Original line number Diff line number Diff line
@@ -86,6 +86,10 @@ automatically purged when the consumer fails to probe or later unbinds. 
This obviates the need to explicitly delete the link in the ``->remove``

callback or in the error path of the ``->probe`` callback.



Similarly, when the device link is added from supplier's ``->probe`` callback,

``DL_FLAG_AUTOREMOVE_SUPPLIER`` causes the device link to be automatically

purged when the supplier fails to probe or later unbinds.



Limitations

===========

drivers/base/core.c

+10 −0
Original line number Diff line number Diff line
@@ -518,6 +518,16 @@ void device_links_driver_cleanup(struct device *dev) 


		WARN_ON(link->flags & DL_FLAG_AUTOREMOVE_CONSUMER);

		WARN_ON(link->status != DL_STATE_SUPPLIER_UNBIND);



		/*

		 * autoremove the links between this @dev and its consumer

		 * devices that are not active, i.e. where the link state

		 * has moved to DL_STATE_SUPPLIER_UNBIND.

		 */

		if (link->status == DL_STATE_SUPPLIER_UNBIND &&

		    link->flags & DL_FLAG_AUTOREMOVE_SUPPLIER)

			kref_put(&link->kref, __device_link_del);



		WRITE_ONCE(link->status, DL_STATE_DORMANT);

	}

include/linux/device.h

+2 −0
Original line number Diff line number Diff line
@@ -787,11 +787,13 @@ enum device_link_state { 
 * AUTOREMOVE_CONSUMER: Remove the link automatically on consumer driver unbind.

 * PM_RUNTIME: If set, the runtime PM framework will use this link.

 * RPM_ACTIVE: Run pm_runtime_get_sync() on the supplier during link creation.

 * AUTOREMOVE_SUPPLIER: Remove the link automatically on supplier driver unbind.

 */

#define DL_FLAG_STATELESS		BIT(0)

#define DL_FLAG_AUTOREMOVE_CONSUMER	BIT(1)

#define DL_FLAG_PM_RUNTIME		BIT(2)

#define DL_FLAG_RPM_ACTIVE		BIT(3)

#define DL_FLAG_AUTOREMOVE_SUPPLIER	BIT(4)



/**

 * struct device_link - Device link representation.

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