[PATCH] of/irq: add missing of_node_put() for interrupt parent node

From: Clément Léger
Date: Tue Jan 17 2023 - 09:47:40 EST


After calling of_irq_parse_one(), the node provided in the of_phandle_args
has a refcount increment by one. Add missing of_node_put in of_irq_get()
to decrement the refcount once used.

Signed-off-by: Clément Léger <clement.leger@xxxxxxxxxxx>
---

While debugging a refcount problem with OF_DYNAMIC enabled (which is
actually the only case were node refcount are really used), I noticed that
platform_get_irq() was actually incrementing the refcount of an interrupt
controller node. Digging into that function shows that it calls
of_irq_get() which calls of_irq_parse_one() and finally of_irq_parse_raw().
Since it seems sane that the node returned in the of_phandle_args has a
refcount incremented, I thought it is better to put the of_node_put() in
the user even though it was hard to find any user doing so.

drivers/of/irq.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index e9bf5236ed89..174900072c18 100644
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -438,10 +438,16 @@ int of_irq_get(struct device_node *dev, int index)
return rc;

domain = irq_find_host(oirq.np);
- if (!domain)
- return -EPROBE_DEFER;
+ if (!domain) {
+ rc = -EPROBE_DEFER;
+ goto out;
+ }

- return irq_create_of_mapping(&oirq);
+ rc = irq_create_of_mapping(&oirq);
+out:
+ of_node_put(oirq.np);
+
+ return rc;
}
EXPORT_SYMBOL_GPL(of_irq_get);

--
2.39.0