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

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Date:   Tue, 22 Aug 2017 14:47:15 +0200
From:   Linus Walleij <linus.walleij@...aro.org>
To:     Rushikesh S Kadam <rushikesh.s.kadam@...el.com>
Cc:     Mika Westerberg <mika.westerberg@...ux.intel.com>,
        Heikki Krogerus <heikki.krogerus@...ux.intel.com>,
        "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>,
        rajneesh.bhardwaj@...el.com, 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 10:23 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>

Excellent work, patch applied with the collected ACKs.

Yours,
Linus Walleij