Am 18.04.2016 um 23:22 schrieb Dmitry Torokhov dmitry.torokhov@gmail.com:
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.
Yes, indeed. It is opposite to the usual object ownership rule that the code fragment that asks for a handle has to release it.
Usually it does not become obvious because often CONFIG_OF_DYNAMIC=n. This disables all of_node refcounting completely so such bugs remain unnoticed.
Any chance we can make it a bit more sane and not drop the reference inside it instead?
Well, if you want to change ~2000 files, test on all platforms and ask Linus for agreement?
Signed-off-by: H. Nikolaus Schaller hns@goldelico.com
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