Re: [RFC][PATCH] gpiolib: add irq_wake (power-management) sysfsfile

From: Russell King - ARM Linux
Date: Tue Nov 15 2011 - 12:21:09 EST


On Tue, Nov 15, 2011 at 01:16:37PM +0000, Mark Brown wrote:
> On Fri, Nov 11, 2011 at 10:40:06AM +0100, Patrick Combes wrote:
> > + else if (sysfs_streq(buf, "enable") || sysfs_streq(buf, "1"))
> > + status = enable_irq_wake(gpio_to_irq(gpio));
> > + else if (sysfs_streq(buf, "disable") || sysfs_streq(buf, "0"))
> > + status = disable_irq_wake(gpio_to_irq(gpio));
> > + else
> > + status = -EINVAL;
>
> ...this doesn't do anything to stop userspace doing multiple enables and
> disables.

It doesn't check whether gpio_to_irq(gpio) returns something sane either.
It should be doing something like this before taking the mutex:

irq = gpio_to_irq(gpio);
if (irq <= 0)
return irq < 0 ? irq : -EINVAL;

and then doing (enable|disable)_irq_wake() on irq.
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