Messages in this thread |  | | Date | Wed, 28 May 2025 22:23:34 +0300 | | From | Dmitry Baryshkov <> | | Subject | Re: [PATCH v2 2/6] ASoC: aoa: Use helper function for_each_child_of_node_scoped() |
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On Mon, May 26, 2025 at 04:20:37PM +0800, Ai Chao wrote: > > Hi Johannes: > > > Hi Johannes: > > > > > > > > "simplifies the code" is no need to callof_node_put() . > > > > Fair. Except that's not what you _actually_ changed here. Like I said, > > > > either it's buggy before or after. > > > > > > > In the function i2sbus_probe, it not return a struct device_node, so , I > > > think function for_each_child_of_node_scoped is better than > > > for_each_child_of_node. > > You still haven't explained why it's even correct. > > > > johannes > > The for_each_child_of_node() function is used to iterate over all child > nodes of a device tree node. > During each iteration, it retrieves a pointer to the child node via > of_get_next_child() and automatically increments the node's reference count > (of_node_get()).
This is not complete story, you missed the second part of it.
> Each call to of_get_next_child() increases the reference count (refcount) of > the returned child node, ensuring that the node is not freed while in use. > for_each_child_of_node() increments the child node's reference count in each > iteration but does not decrement it automatically. > If of_node_put() is not called manually, the reference count will never > reach zero, resulting in a memory leak of the node. > > Best regards, > Ai Chao
-- With best wishes Dmitry
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