Re: [PATCH][resubmit] TPM: update char dev BKL pushdown

["Serge E. Hallyn" <serue@us.ibm.com>]

Quoting Alan Cox (alan@lxorguk.ukuu.org.uk):
> > +	atomic_set(&chip->is_open, 1);
> > +	get_device(chip->dev); /* protect from chip disappearing */
> 
> Why not just use test_and_set_bit() ? You seem to be abusing atomic_t to
> achieve this.

Good point.  Or heck just make it a simple flag.  Earlier I thought there
was a place where driver_lock was taken just to do num_opens--, and so
replacing the int num_opens with an atomic_t seemed worthwhile.  But since
is_open is a boolean and now seems to be always protected by driver_lock,
a flag seems best.

-serge