On Mon, Mar 28, 2016 at 3:32 PM, Okash Khawaja [off-list ref] wrote:

Hi,

I'm writing a i2c device driver. In probe(), among other things I call:

polled_input = input_allocate_polled_device();
input_register_polled_device(polled_input);

Then inside remove(), I extract the instance of input_polled_dev and
call

input_unregister_polled_device(polled_input);

This results in kernel error:

"Unable to handle kernel NULL pointer dereference at virtual address
00000474".

It turns out that the input_dev pointer inside input_polled_dev is null
which leads to this error. But why is input_dev pointer null? It is not
null inside probe() function and I don't release it anywhere.

This is code: http://pastebin.com/JJdepyEG and here is link to the output,
along with my log statements: http://pastebin.com/badwSvyy.

input_free_polled_device(polled_input) is always called in your probe function.


-- 
Carlo Caione