Re: [patch 2.6.31-rc7] gpiolib: allow poll() on value

David Brownell
2009-09-02T04:38:08Z

On Tuesday 01 September 2009, Andrew Morton wrote:
> > ...
> >
> > +static struct idr pdesc_idr;
>
> There's no locking to protect this tree.  If that isn't a bug then I'd
> suggest that a comment be added here explaining why.

Covered by mutex_lock(&sysfs_lock) calls per a quick re-read...

> > +static irqreturn_t gpio_sysfs_irq(int irq, void *priv)
> > +{
> > +     struct work_struct      *work = priv;
> > +
> > +     schedule_work(work);
> > +     return IRQ_HANDLED;
> > +}
>
> The only place where we explicitly cancel the pending work is in
> gpio_setup_irq().  Is that sufficient?  Is there any way in which the
> work callback can occur after things have been
> freed/closed/deinitialised/etc?

Not that I noticed; it's not supposed to be possible to
free/etc with IRQs active.

- Dave