On Tue, Apr 19, 2016 at 09:43:08AM +0200, H. Nikolaus Schaller wrote:
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?
It's not that bad, let's see what DT maintainers say to the patch I posted...