[v2,1/6] device property: document device_for_each_child_node macro

Commit Message

Javier Carrasco July 21, 2024, 3:19 p.m. UTC

There have been some misconceptions about this macro, which iterates
over available child nodes from different backends.

As that is not obvious by its name, some users have opted for the
`fwnode_for_each_available_child_node()` macro instead.
That requires an unnecessary, explicit access to the fwnode member
of the device structure.

Passing the device to `device_for_each_child_node()` is shorter,
reflects more clearly the nature of the child nodes, and renders the
same result.

In general, `fwnode_for_each_available_child_node()` should be used
whenever the parent node of the children to iterate over is a firmware
node, and not the device itself.

Document the `device_for_each_child node(dev, child)` macro to clarify
its functionality.

Suggested-by: Jonathan Cameron <[e-mail]>
Reviewed-by: Jonathan Cameron <[e-mail]>
Signed-off-by: Javier Carrasco <[e-mail]>
---
 include/linux/property.h | 10 ++++++++++
 1 file changed, 10 insertions(+)

Comments

Markus Elfring July 22, 2024, 7:15 a.m. UTC | #1

…
> + * Unavailable nodes are skipped i.e. this macro is implicitly _available_.
…

How good does presented information fit together in this comment line?

Regards,
Markus

Greg Kroah-Hartman July 22, 2024, 7:40 a.m. UTC | #2

On Mon, Jul 22, 2024 at 09:15:26AM +0200, Markus Elfring wrote:
> …
> > + * Unavailable nodes are skipped i.e. this macro is implicitly _available_.
> …
> 
> How good does presented information fit together in this comment line?


Hi,

This is the semi-friendly patch-bot of Greg Kroah-Hartman.

Markus, you seem to have sent a nonsensical or otherwise pointless
review comment to a patch submission on a Linux kernel developer mailing
list.  I strongly suggest that you not do this anymore.  Please do not
bother developers who are actively working to produce patches and
features with comments that, in the end, are a waste of time.

Patch submitter, please ignore Markus's suggestion; you do not need to
follow it at all.  The person/bot/AI that sent it is being ignored by
almost all Linux kernel maintainers for having a persistent pattern of
behavior of producing distracting and pointless commentary, and
inability to adapt to feedback.  Please feel free to also ignore emails
from them.

thanks,

greg k-h's patch email bot

Patch

diff --git a/include/linux/property.h b/include/linux/property.h
index 61fc20e5f81f..da8f1208de38 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -171,6 +171,16 @@  struct fwnode_handle *fwnode_get_next_available_child_node(
 struct fwnode_handle *device_get_next_child_node(const struct device *dev,
 						 struct fwnode_handle *child);
 
+/**
+ * device_for_each_child_node - iterate over available child nodes of a device
+ * @dev: Pointer to the struct device
+ * @child: Pointer to an available child node in each loop iteration
+ *
+ * Unavailable nodes are skipped i.e. this macro is implicitly _available_.
+ * The reference to the child node must be dropped on early exits.
+ * See fwnode_handle_put().
+ * For a scoped version of this macro, use device_for_each_child_node_scoped().
+ */
 #define device_for_each_child_node(dev, child)				\
 	for (child = device_get_next_child_node(dev, NULL); child;	\
 	     child = device_get_next_child_node(dev, child))