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

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Date:   Fri, 11 Aug 2017 11:52:35 +0300
From:   Mika Westerberg <mika.westerberg@...ux.intel.com>
To:     Rushikesh S Kadam <rushikesh.s.kadam@...el.com>
Cc:     heikki.krogerus@...ux.intel.com, linus.walleij@...aro.org,
        linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org,
        tglx@...utronix.de, rajneesh.bhardwaj@...el.com,
        andy@...radead.org, rjw@...ysocki.net
Subject: Re: [PATCH] pinctrl: intel: Disable GPIO pin interrupts in suspend

On Fri, Aug 11, 2017 at 01:53:44PM +0530, Rushikesh S Kadam 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.

This is really good changelog!

> Signed-off-by: Rushikesh S Kadam <rushikesh.s.kadam@...el.com>

Acked-by: Mika Westerberg <mika.westerberg@...ux.intel.com>