On Wed, Apr 02, 2014 at 05:53:54PM +0100, Mark Brown wrote: > To make this correct we need to at least ensure that the node passed > into the regulator API is valid and referenced at that time so there > should only be an issue for the core if the reference is dropped after > that. In the above case the device model is holding a reference since > this is the of_node for the device itself so taking the reference won't > hurt but is redundant. In cases where we have more than one regulator > and are using of_regulator_match() then things are more tricky. > Something needs to drop the references it returns (which isn't happening > at all at the minute).
>From what I can see of_regulator_match isn't taking any references at the minute? for_each_child_of_node will get a reference but it will also put that when we process the next child. We copy the pointer to the child into match->of_node but don't manually increment the reference at all. So of_regulator_match has no effect on the reference count of the of_node. > Doing it while doing the match and register > seems simple and neat from an error handling point of view so having the > core take an additional reference during the registration would join up > with that. The main issue I have is that devm_regualtor_register is a bit awkward. With regulator_register you will always be calling regulator_unregister so you can put the of_node there but with devm there isn't really a good place to put the of_node. Would perhaps a sensible thing here be to add an of_node_get to of_regulator_match, since we seem to be expecting that to increase the ref count. And then just add an of_node_put to regulator_unregister. And for anything directly using regulator_register/devm_regulator_register they should add a manual of_node_get? Thanks, Charles -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
