On 02/03/2023 08:49, Geert Uytterhoeven wrote:
Hi Jean-Jacques,
Thanks for your patch!
On Wed, Mar 1, 2023 at 7:53 PM Jean-Jacques Hiblot
<jjhiblot@xxxxxxxxxxxxxxx> wrote:
of_irq_parse_one() does a get() on the device node returned in out_irq->np.
Callers of of_irq_parse_one() must do a put() when they are done with it.
What does "be done with it" really mean here?
Signed-off-by: Jean-Jacques Hiblot <jjhiblot@xxxxxxxxxxxxxxx>
--- a/arch/arm/mach-shmobile/regulator-quirk-rcar-gen2.c
+++ b/arch/arm/mach-shmobile/regulator-quirk-rcar-gen2.c
@@ -184,6 +184,7 @@ static int __init rcar_gen2_regulator_quirk(void)
kfree(quirk);
continue;
}
+ of_node_put(argsa->np);
The quirk object, which is a container of argsa, is still used below,
and stored in a linked list. I agree argsa->np is not dereferenced,
but the pointer itself is still compared to other pointers.
Hi Geert,
I fail to see when the pointers are compared. It looks to me that only
the args are compared. Am I missing something ?
In any case, looking more closely at the code, I guess that indeed the
of_node_put() shouldn't be added here because this code expects that the
nodes never go away. That is probably a good assertion in case of PMICs
JJ
IIUIC, calling of_node_put() might cause the reference count to drop to
zero, and the underlying struct node object to be deallocated.
So when a future reference to the same DT node will be taken, a new
struct node object will be allocated, and the pointer comparison below
will fail?
Or am I missing something?
Gr{oetje,eeting}s,
Geert
