On Mon, Apr 29, 2013 at 08:47:37PM +0300, Leon Romanovsky wrote: > On Mon, Apr 29, 2013 at 1:19 PM, Mark Brown <broonie@xxxxxxxxxx> wrote: > > On Sun, Apr 28, 2013 at 09:32:18PM +0300, Leon Romanovsky wrote: > > > >> I think the reason of our misunderstanding is due to the name of > >> input_free_device call. From the code, it is device destroy function, > >> and the freeing itself done as an error handling of > >> input_register_device > >> (http://lxr.free-electrons.com/source/drivers/input/input.c#L2114). > > > >> How do you think we need to proceed? Do I need to send patches with > >> explicit call to input_free_device function? > > > > I really think the input API needs to be looked at here, this is all way > > too error prone. Calling input_free_device() on something allocated > > using devm_ looks like an error itself... > In general, I agree with you, but I think we both agree that the > current patch is not working as expected. > The problem is that you allocated device with devm_ and later at the > code you tried to register it, but failed. In this case no one will > call to devres_destroy, because it is done at unregister stage only. > > I see two possible solutions: > 1. short one - fix your patches > 2. long one - add input_free_device code into input_register_device > call (http://lxr.free-electrons.com/source/drivers/input/input.c#L2114). > The rules are pretty straightforward: 1. If you are using devm_input_allocate_device() you do not need to call input_free_device() nor input_unregister_device() - the core will create a devres structure for freeing the device and if input_register_device() succeeds it will also add a 2nd devres for unregistering. This way the "normal" unwind is a 2-step process with device is "half alive" and being able to survive input_event() calls from IRQ handlers if they are still alive. IOW it should all "just work". 2. If you are using input_allocate_device() then you need to call input_free_device() until you called input_register_device(), afterward input_unregister_device() should be called. Thanks. -- Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
