Re: [PATCH] Input: sparse-keymap - add managed version of sparse_keymap_setup()

On Tue, Feb 28, 2017 at 10:45:25AM +0100, Michał Kępień wrote:

Some platform drivers use devm_input_allocate_device() together with
sparse_keymap_setup() in their .probe callbacks.  While using the former
simplifies error handling, using the latter necessitates calling
sparse_keymap_free() in the error path and upon module unloading to
avoid leaking the copy of the keymap allocated by sparse_keymap_setup().

To help prevent such leaks and enable simpler error handling in these
drivers, add a new function which allows automatic freeing of the keymap
copy upon probe failure and on driver detach.

As devm_input_allocate_device() adds its devres to the device owning the
input device, we do the same for managed input devices to ensure freeing
the keymap copy is properly slotted in the devres stack.

The new function can also be used by non-managed input devices, though
in this case the devres is attached to the struct device embedded inside
the input device itself.

This is wrong and does not work as input devices are never probed and
never unbound, so the cleanup will never happen.

Either pass device explicitly, or always take input's parent.

Thanks.

-- 
Dmitry