Re: [PATCH] GPIO button wth wakeup attribute is supposed to wake the system up
From: Rafael J. Wysocki
Date: Tue Jul 08 2014 - 16:48:17 EST
On Tuesday, July 08, 2014 01:45:30 PM Dmitry Torokhov wrote:
> On Tue, Jul 08, 2014 at 10:52:52PM +0200, Rafael J. Wysocki wrote:
> > On Thursday, June 19, 2014 08:51:25 AM Li, Aubrey wrote:
> > > When the wakeup attribute is set, the GPIO button is capable of
> > > waking up the system from sleep states, including the "freeze"
> > > sleep state. For that to work, its driver needs to pass the
> > > IRQF_NO_SUSPEND flag to devm_request_any_context_irq(), or the
> > > interrupt will be disabled by suspend_device_irqs() and the
> > > system won't be woken up by it from the "freeze" sleep state.
> > >
> > > The suspend_device_irqs() routine is a workaround for drivers
> > > that mishandle interrupts triggered when the devices handled
> > > by them are suspended, so it is safe to use IRQF_NO_SUSPEND in
> > > all drivers that don't have that problem.
> > >
> > > The affected/tested machines include Dell Venue 11 Pro and Asus T100TA.
> > >
> > > Signed-off-by: Aubrey Li <aubrey.li@xxxxxxxxxxxxxxx>
> > > Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> > OK
> > Due to the lack of response (ie. no objections) and because the issue
> > addressed by this patch is real, I'm queuing it up as a PM-related fix
> > for 3.17.
> Please do not. The response is till the same: board code should make sure
> that enable_irq_wake() does the right thing and keeps interrupts enabled.
Which board code? That's nothing like that for the platforms in question.
> It is wrong to patch drivers for this.
Why is it? Only drivers know if they can handle incoming interrupts after
having suspended their devices.
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