Re: [PATCH v2] HID: Replace semaphore driver_lock with mutex

[David Herrmann]

Hi

On Tue, Jun 13, 2017 at 11:56 AM, Benjamin Tissoires
<benjamin.tissoires@xxxxxxxxxx> wrote:
>> > -       struct semaphore driver_lock;                                   /* protects the current driver, except during input */
>> > +       struct mutex driver_lock;                                       /* protects the current driver, except during input */
>> >         struct semaphore driver_input_lock;                             /* protects the current driver */
>
> Unless I am mistaken, this one could also be converted to a mutex (in a
> separate patch, of course).

The mutex code clearly states mutex_trylock() must not be used in
interrupt context (see kernel/locking/mutex.c), hence we used a
semaphore here. Unless the mutex code is changed to allow this, we
cannot switch away from semaphores.

Otherwise, this patch (given Benjamin's comments are addressed) looks good:

Reviewed-by: David Herrmann <dh.herrmann@xxxxxxxxx>

Thanks
David