linux-kernel - Re: [PATCH] PM / sleep / irq: Do not suspend wakeup interrupts

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Date:	Tue, 15 Jul 2014 14:36:46 +0200
From:	Alexander Stein <alexander.stein@...tec-electronic.com>
To:	"Rafael J. Wysocki" <rjw@...ysocki.net>
Cc:	Thomas Gleixner <tglx@...utronix.de>,
	"Li, Aubrey" <aubrey.li@...ux.intel.com>,
	Dmitry Torokhov <dmitry.torokhov@...il.com>,
	"linux-input@...r.kernel.org" <linux-input@...r.kernel.org>,
	LKML <linux-kernel@...r.kernel.org>,
	One Thousand Gnomes <gnomes@...rguk.ukuu.org.uk>,
	Linux PM list <linux-pm@...r.kernel.org>
Subject: Re: [PATCH] PM / sleep / irq: Do not suspend wakeup interrupts

On Tuesday 15 July 2014 14:50:28, Rafael J. Wysocki wrote:
> On Tuesday, July 15, 2014 02:22:25 PM Alexander Stein wrote:
> > On Thursday 10 July 2014 23:37:54, Rafael J. Wysocki wrote:
> > > From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> > > 
> > > If an IRQ has been configured for wakeup via enable_irq_wake(), the
> > > driver who has done that must be prepared for receiving interrupts
> > > after suspend_device_irqs() has returned, so there is no need to
> > > "suspend" such IRQs.  Moreover, if drivers using enable_irq_wake()
> > > actually want to receive interrupts after suspend_device_irqs() has
> > > returned, they need to add IRQF_NO_SUSPEND to the IRQ flags while
> > > requesting the IRQs, which shouldn't be necessary (it also goes a bit
> > > too far, as IRQF_NO_SUSPEND causes the IRQ to be ignored by
> > > suspend_device_irqs() all the time regardless of whether or not it
> > > has been configured for signaling wakeup).
> > > 
> > > For the above reasons, make __disable_irq() ignore IRQ descriptors
> > > with IRQD_WAKEUP_STATE set when its suspend argument is true which
> > > effectively causes them to behave like IRQs with IRQF_NO_SUSPEND
> > > set.
> > > 
> > > This also allows IRQs configured for wakeup via enable_irq_wake()
> > > to work as wakeup interrupts for the "freeze" (suspend-to-idle)
> > > sleep mode automatically just like for any other sleep states.
> > > 
> > > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> > > ---
> > >  kernel/irq/manage.c |    3 ++-
> > >  1 file changed, 2 insertions(+), 1 deletion(-)
> > > 
> > > Index: linux-pm/kernel/irq/manage.c
> > > ===================================================================
> > > --- linux-pm.orig/kernel/irq/manage.c
> > > +++ linux-pm/kernel/irq/manage.c
> > > @@ -385,7 +385,8 @@ setup_affinity(unsigned int irq, struct
> > >  void __disable_irq(struct irq_desc *desc, unsigned int irq, bool suspend)
> > >  {
> > >  	if (suspend) {
> > > -		if (!desc->action || (desc->action->flags & IRQF_NO_SUSPEND))
> > > +		if (!desc->action || (desc->action->flags & IRQF_NO_SUSPEND)
> > > +		    || irqd_has_set(&desc->irq_data, IRQD_WAKEUP_STATE))
> > >  			return;
> > >  		desc->istate |= IRQS_SUSPENDED;
> > >  	}
> > 
> > Nice, this fixes my wakeup problem from freeze using gpio-keys. Unfortunately my SPI-attached touchscreen controller cannot be used for wakeup from freeze. Using it to wakeup from mem does work instead. Any ideas what might be wrong in this case?
> 
> Not without looking at the code in question.
> 
> One guess would be a missing call to enable_irq_wake().

No, ads7846.c does call 'enable_irq_wake(ts->spi->irq)'. So is this a platform or driver specific problem?

Regards,
Alexander

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