Re: [PATCH 1/5] input: twl6040-vibra: fix DT node memory management

From: Dmitry Torokhov
Date: Mon Apr 18 2016 - 17:22:09 EST


On Mon, Apr 18, 2016 at 09:55:37PM +0200, H. Nikolaus Schaller wrote:
> commit e7ec014a47e4 ("Input: twl6040-vibra - update for device tree support")
>
> made the separate vibra DT node to a subnode of the twl6040.
>
> It now calls of_find_node_by_name() to locate the "vibra" subnode.
> This function has a side effect to call of_node_put on() for the twl6040
> parent node passed in as a parameter. This causes trouble later on.
>
> Solution: we must call of_node_get() before of_find_node_by_name()

God, what messed up API. Any chance we can make it a bit more sane and
not drop the reference inside it instead?

>
> Signed-off-by: H. Nikolaus Schaller <hns@xxxxxxxxxxxxx>
> ---
> drivers/input/misc/twl6040-vibra.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/input/misc/twl6040-vibra.c b/drivers/input/misc/twl6040-vibra.c
> index ea63fad..7221a00 100644
> --- a/drivers/input/misc/twl6040-vibra.c
> +++ b/drivers/input/misc/twl6040-vibra.c
> @@ -262,6 +262,7 @@ static int twl6040_vibra_probe(struct platform_device *pdev)
> int vddvibr_uV = 0;
> int error;
>
> + of_node_get(twl6040_core_dev->of_node);
> twl6040_core_node = of_find_node_by_name(twl6040_core_dev->of_node,
> "vibra");
> if (!twl6040_core_node) {
> --
> 2.7.3
>

--
Dmitry