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Date: Tue, 15 Nov 2011 17:20:53 +0000
From: Russell King - ARM Linux <linux@arm.linux.org.uk>
To: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Patrick Combes <p-combes@ti.com>, grant.likely@secretlab.ca,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        Hugo Dupras <h-dupras@ti.com>
Subject: Re: [RFC][PATCH] gpiolib: add irq_wake (power-management) sysfs
	file
Message-ID: <20111115172053.GB9581@n2100.arm.linux.org.uk>
References: <1321004406-15663-1-git-send-email-p-combes@ti.com> <20111115131636.GA31028@sirena.org.uk>
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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.