linux-kernel - Re: [PATCH] pinctrl: intel: Disable GPIO pin interrupts in suspend

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Date:   Fri, 11 Aug 2017 15:38:52 +0530
From:   Rajneesh Bhardwaj <rajneesh.bhardwaj@...el.com>
To:     Andy Shevchenko <andy.shevchenko@...il.com>
Cc:     Rushikesh S Kadam <rushikesh.s.kadam@...el.com>,
        Mika Westerberg <mika.westerberg@...ux.intel.com>,
        "Krogerus, Heikki" <heikki.krogerus@...ux.intel.com>,
        Linus Walleij <linus.walleij@...aro.org>,
        "linux-gpio@...r.kernel.org" <linux-gpio@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Andy Shevchenko <andy@...radead.org>,
        "Rafael J. Wysocki" <rjw@...ysocki.net>
Subject: Re: [PATCH] pinctrl: intel: Disable GPIO pin interrupts in suspend

On Fri, Aug 11, 2017 at 12:57:26PM +0300, Andy Shevchenko wrote:
> On Fri, Aug 11, 2017 at 11:23 AM, Rushikesh S Kadam
> <rushikesh.s.kadam@...el.com> wrote:
> > The fix prevents unintended wakes from second level GPIO pin interrupts.
> >
> > On some Intel Kabylake platforms, it is observed that GPIO pin interrupts
> > can wake the platform from suspend-to-idle, even though the IRQ is not
> > configured as IRQF_NO_SUSPEND or enable_irq_wake().
> >
> > This can cause undesired wakes on Mobile devices such as Laptops and
> > Chromebook devices. For example a headset jack insertion is not a desired
> > wake source on Chromebook devices.
> >
> > The pinctrl-intel (GPIO controller) driver implements a "Shared IRQ" model.
> > All GPIO pin interrupts are OR'ed and mapped to a first level IRQ14 (or
> > IRQ15). The driver registers an irq_chip struct and maps an irq_domain for
> > the GPIO pin interrupts. The IRQ14 handler demuxes and calls the second
> > level IRQ for the respective pin.
> >
> > In the suspend entry flow, at suspend_noirq stage, the kernel disables IRQs
> > that are not marked for wake. The pinctrl-intel driver does not implement a
> > irq_disable()  callback (to take advantage of lazy disabling). The
> > pinctrl-intel GPIO interrupts are not disabled in hardware during suspend
> > entry, and thus are able to wake the SoC out of suspend-to-idle.
> >
> > This patch sets the IRQCHIP_MASK_ON_SUSPEND flag for the GPIO irq_chip, to
> > disable the second level interrupts at suspend_noirq stage via the irq_mask
> > callbacks. The irq_mask callback disables the IRQs in hardware by
> > programming the corresponding GPIO pad registers. Only IRQs that are not
> > marked for wake are disabled.
> >
> > Signed-off-by: Rushikesh S Kadam <rushikesh.s.kadam@...el.com>
> 
> Reviewed-by: Andy Shevchenko <andy.shevchenko@...il.com>

Reviewed-and-tested-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@...el.com>

> 
> > ---
> >  drivers/pinctrl/intel/pinctrl-intel.c | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/drivers/pinctrl/intel/pinctrl-intel.c b/drivers/pinctrl/intel/pinctrl-intel.c
> > index 6dc1096..8f87215 100644
> > --- a/drivers/pinctrl/intel/pinctrl-intel.c
> > +++ b/drivers/pinctrl/intel/pinctrl-intel.c
> > @@ -1035,6 +1035,7 @@ static irqreturn_t intel_gpio_irq(int irq, void *data)
> >         .irq_unmask = intel_gpio_irq_unmask,
> >         .irq_set_type = intel_gpio_irq_type,
> >         .irq_set_wake = intel_gpio_irq_wake,
> > +       .flags = IRQCHIP_MASK_ON_SUSPEND,
> >  };
> >
> >  static int intel_gpio_probe(struct intel_pinctrl *pctrl, int irq)
> > --
> > 1.9.1
> >
> 
> 
> 
> -- 
> With Best Regards,
> Andy Shevchenko

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