Re: [PATCH v1] irqchip/gic-v3-its: Drop ITS node reference on its_of_probe() errors

[Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>]

On Wed, 23 Sep 2026 12:54:40 -0400
Yuho Choi <oss.patchbox@gmail.com> wrote:

> its_of_probe() walks the ITS nodes with of_find_matching_node(), which
> drops the reference on the previous node and returns the next one with
> its reference count raised.  The loops are balanced when they run to the
> end, but the three error returns (a failed its_reset_one(), a failed
> its_node_init() and a failed its_probe_one()) leave with the current
> node still referenced.
> 
> Drop it before returning.
> 
> Fixes: c733ebb7cb67 ("irqchip/gic-v3-its: Reset each ITS's BASERn register before probe")
> Fixes: 9585a495ac93 ("irqchip/gic-v3-its: Split allocation from initialisation of its_node")
> Signed-off-by: Yuho Choi <oss.patchbox@gmail.com>

I only took a very quick look but why can't this use for_each_matching_node()

That doesn't solve your problem but it would be easy to add a for_each_matching_node_scoped()
in similar spirit to for_each_child_of_node_scoped() I think and that would give you a cleaner fix here.

There may well be other places such a macro would benefit. I just haven't looked!

Jonathan


> ---
> Compile-tested only (arm64 defconfig, W=1).
> 
>  drivers/irqchip/irq-gic-v3-its.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
> index e9807af23537..6361d20bd920 100644
> --- a/drivers/irqchip/irq-gic-v3-its.c
> +++ b/drivers/irqchip/irq-gic-v3-its.c
> @@ -5579,8 +5579,10 @@ static int __init its_of_probe(struct device_node *node)
>  			continue;
>  
>  		err = its_reset_one(&res);
> -		if (err)
> +		if (err) {
> +			of_node_put(np);
>  			return err;
> +		}
>  	}
>  
>  	for (np = of_find_matching_node(node, its_device_id); np;
> @@ -5602,12 +5604,15 @@ static int __init its_of_probe(struct device_node *node)
>  
>  
>  		its = its_node_init(&res, &np->fwnode, of_node_to_nid(np));
> -		if (!its)
> +		if (!its) {
> +			of_node_put(np);
>  			return -ENOMEM;
> +		}
>  
>  		err = its_probe_one(its);
>  		if (err)  {
>  			its_node_destroy(its);
> +			of_node_put(np);
>  			return err;
>  		}
>  	}
> 
> base-commit: f0100363d8c374bd8e9ea7c9ba02744f0b802ca4