Re: [PATCH v2 RESEND] gpiolib: Add pin change notification

[Ben Nizette <bn@niasdigital.com>]

On Tue, 2008-10-21 at 13:31 -0700, Andrew Morton wrote:
> On Tue, 21 Oct 2008 09:50:06 +1100
> Ben Nizette <bn@niasdigital.com> wrote:
> > +static irqreturn_t gpio_irq_handler(int irq, void *dev_id)
> > +{
> > +	struct gpio_desc *desc = dev_id;
> > +	int gpio = desc - gpio_desc;
> > +	int new, old;
> > +
> > +	if (!gpio_is_valid(gpio))
> > +		return IRQ_NONE;
> > +
> > +	new = gpio_get_value(gpio);
> > +	old = desc->val;
> > +
> > +	if ((new && !old && test_bit(ASYNC_RISING, &desc->flags)) ||
> > +	    (!new && old && test_bit(ASYNC_FALLING, &desc->flags)))
> > +		sysfs_notify(&desc->dev->kobj, NULL, "value");
> 
> eekeekeek!  sysfs_notify() does mutex_lock() and will die horridly if
> called from an interrupt handler.
> 
> You should have got a storm of warnings when runtime testing this code.
> Please ensure that all debug options are enabled when testing code. 
> Documentation/SubmitChecklist has help.

0_o yea that isn't great...  Thanks - shall respin and repost shortly.


	--Ben.