diff mbox series

[v1,11/18] driver core: Redefine the meaning of fwnode_operations.add_links()

Message ID 20201104232356.4038506-12-saravanak@google.com
State New
Headers show
Series [v1,01/18] Revert "driver core: Avoid deferred probe due to fw_devlink_pause/resume()" | expand

Commit Message

Saravana Kannan Nov. 4, 2020, 11:23 p.m. UTC
Change the meaning of fwnode_operations.add_links() to just create
fwnode links by parsing the properties of a given fwnode.

This patch doesn't actually make any code changes. To keeps things more
digestable, the actual functional changes come in later patches in this
series.

Signed-off-by: Saravana Kannan <saravanak@google.com>
---
 include/linux/fwnode.h | 42 +++---------------------------------------
 1 file changed, 3 insertions(+), 39 deletions(-)

Comments

Rafael J. Wysocki Nov. 16, 2020, 4:16 p.m. UTC | #1
On Thu, Nov 5, 2020 at 12:24 AM Saravana Kannan <saravanak@google.com> wrote:
>

> Change the meaning of fwnode_operations.add_links() to just create

> fwnode links by parsing the properties of a given fwnode.

>

> This patch doesn't actually make any code changes. To keeps things more

> digestable, the actual functional changes come in later patches in this

> series.

>

> Signed-off-by: Saravana Kannan <saravanak@google.com>

> ---

>  include/linux/fwnode.h | 42 +++---------------------------------------

>  1 file changed, 3 insertions(+), 39 deletions(-)

>

> diff --git a/include/linux/fwnode.h b/include/linux/fwnode.h

> index afde643f37a2..ec02e1e939cc 100644

> --- a/include/linux/fwnode.h

> +++ b/include/linux/fwnode.h

> @@ -78,44 +78,8 @@ struct fwnode_reference_args {

>   *                            endpoint node.

>   * @graph_get_port_parent: Return the parent node of a port node.

>   * @graph_parse_endpoint: Parse endpoint for port and endpoint id.

> - * @add_links: Called after the device corresponding to the fwnode is added

> - *             using device_add(). The function is expected to create device

> - *             links to all the suppliers of the device that are available at

> - *             the time this function is called.  The function must NOT stop

> - *             at the first failed device link if other unlinked supplier

> - *             devices are present in the system.  This is necessary for the

> - *             driver/bus sync_state() callbacks to work correctly.

> - *

> - *             For example, say Device-C depends on suppliers Device-S1 and

> - *             Device-S2 and the dependency is listed in that order in the

> - *             firmware.  Say, S1 gets populated from the firmware after

> - *             late_initcall_sync().  Say S2 is populated and probed way

> - *             before that in device_initcall(). When C is populated, if this

> - *             add_links() function doesn't continue past a "failed linking to

> - *             S1" and continue linking C to S2, then S2 will get a

> - *             sync_state() callback before C is probed. This is because from

> - *             the perspective of S2, C was never a consumer when its

> - *             sync_state() evaluation is done. To avoid this, the add_links()

> - *             function has to go through all available suppliers of the

> - *             device (that corresponds to this fwnode) and link to them

> - *             before returning.

> - *

> - *             If some suppliers are not yet available (indicated by an error

> - *             return value), this function will be called again when other

> - *             devices are added to allow creating device links to any newly

> - *             available suppliers.

> - *

> - *             Return 0 if device links have been successfully created to all

> - *             the known suppliers of this device or if the supplier

> - *             information is not known.

> - *

> - *             Return -ENODEV if the suppliers needed for probing this device

> - *             have not been registered yet (because device links can only be

> - *             created to devices registered with the driver core).

> - *

> - *             Return -EAGAIN if some of the suppliers of this device have not

> - *             been registered yet, but none of those suppliers are necessary

> - *             for probing the device.

> + * @add_links: Create fwnode links to all the suppliers of the fwnode. Return

> + *             zero on success, a negative error code otherwise.


I'd say something like "Create fwnode links to all nodes that
represent devices supplying resources to the device represented by the
current fwnode.  Return ..., or a negative ... on failure."

>   */

>  struct fwnode_operations {

>         struct fwnode_handle *(*get)(struct fwnode_handle *fwnode);

> @@ -155,7 +119,7 @@ struct fwnode_operations {

>         (*graph_get_port_parent)(struct fwnode_handle *fwnode);

>         int (*graph_parse_endpoint)(const struct fwnode_handle *fwnode,

>                                     struct fwnode_endpoint *endpoint);

> -       int (*add_links)(const struct fwnode_handle *fwnode,

> +       int (*add_links)(struct fwnode_handle *fwnode,

>                          struct device *dev);

>  };

>

> --

> 2.29.1.341.ge80a0c044ae-goog

>
diff mbox series

Patch

diff --git a/include/linux/fwnode.h b/include/linux/fwnode.h
index afde643f37a2..ec02e1e939cc 100644
--- a/include/linux/fwnode.h
+++ b/include/linux/fwnode.h
@@ -78,44 +78,8 @@  struct fwnode_reference_args {
  *			       endpoint node.
  * @graph_get_port_parent: Return the parent node of a port node.
  * @graph_parse_endpoint: Parse endpoint for port and endpoint id.
- * @add_links:	Called after the device corresponding to the fwnode is added
- *		using device_add(). The function is expected to create device
- *		links to all the suppliers of the device that are available at
- *		the time this function is called.  The function must NOT stop
- *		at the first failed device link if other unlinked supplier
- *		devices are present in the system.  This is necessary for the
- *		driver/bus sync_state() callbacks to work correctly.
- *
- *		For example, say Device-C depends on suppliers Device-S1 and
- *		Device-S2 and the dependency is listed in that order in the
- *		firmware.  Say, S1 gets populated from the firmware after
- *		late_initcall_sync().  Say S2 is populated and probed way
- *		before that in device_initcall(). When C is populated, if this
- *		add_links() function doesn't continue past a "failed linking to
- *		S1" and continue linking C to S2, then S2 will get a
- *		sync_state() callback before C is probed. This is because from
- *		the perspective of S2, C was never a consumer when its
- *		sync_state() evaluation is done. To avoid this, the add_links()
- *		function has to go through all available suppliers of the
- *		device (that corresponds to this fwnode) and link to them
- *		before returning.
- *
- *		If some suppliers are not yet available (indicated by an error
- *		return value), this function will be called again when other
- *		devices are added to allow creating device links to any newly
- *		available suppliers.
- *
- *		Return 0 if device links have been successfully created to all
- *		the known suppliers of this device or if the supplier
- *		information is not known.
- *
- *		Return -ENODEV if the suppliers needed for probing this device
- *		have not been registered yet (because device links can only be
- *		created to devices registered with the driver core).
- *
- *		Return -EAGAIN if some of the suppliers of this device have not
- *		been registered yet, but none of those suppliers are necessary
- *		for probing the device.
+ * @add_links:	Create fwnode links to all the suppliers of the fwnode. Return
+ *		zero on success, a negative error code otherwise.
  */
 struct fwnode_operations {
 	struct fwnode_handle *(*get)(struct fwnode_handle *fwnode);
@@ -155,7 +119,7 @@  struct fwnode_operations {
 	(*graph_get_port_parent)(struct fwnode_handle *fwnode);
 	int (*graph_parse_endpoint)(const struct fwnode_handle *fwnode,
 				    struct fwnode_endpoint *endpoint);
-	int (*add_links)(const struct fwnode_handle *fwnode,
+	int (*add_links)(struct fwnode_handle *fwnode,
 			 struct device *dev);
 };