Re: [PATCH] powerpc: kernel: pci_dn: Add missing of_node_put() for of_get_xx API

[Tyrel Datwyler <tyreld@linux.ibm.com>]

On 7/1/22 06:17, Liang He wrote:
> In pci_add_device_node_info(), we should use of_node_put() for the
> reference 'parent' returned by of_get_parent() to keep refcount
> balance.
> 
> Fixes: cca87d303c85 ("powerpc/pci: Refactor pci_dn")
> Co-authored-by: Miaoqian Lin <linmq006@gmail.com>
> Signed-off-by: Liang He <windhl@126.com>
> ---
>  arch/powerpc/kernel/pci_dn.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/arch/powerpc/kernel/pci_dn.c b/arch/powerpc/kernel/pci_dn.c
> index 938ab8838ab5..aa221958007e 100644
> --- a/arch/powerpc/kernel/pci_dn.c
> +++ b/arch/powerpc/kernel/pci_dn.c
> @@ -330,6 +330,7 @@ struct pci_dn *pci_add_device_node_info(struct pci_controller *hose,
>  	INIT_LIST_HEAD(&pdn->list);
>  	parent = of_get_parent(dn);
>  	pdn->parent = parent ? PCI_DN(parent) : NULL;
NACK

pdn->parent is now a long term reference so we should not do a put on parent
until we pdn->parent is no longer valid.

-Tyrel

> +	of_node_put(parent);
>  	if (pdn->parent)
>  		list_add_tail(&pdn->list, &pdn->parent->child_list);
>