Linux-ARM-Kernel Archive on
 help / color / Atom feed
From: Marc Zyngier <>
To: Stephen Boyd <>, Thomas Gleixner <>
	Lina Iyer <>
Subject: Re: [PATCH v2] genirq: Respect IRQCHIP_SKIP_SET_WAKE in irq_chip_set_wake_parent()
Date: Tue, 26 Mar 2019 11:11:56 +0000
Message-ID: <> (raw)
In-Reply-To: <>

Hi Stephen,

On 25/03/2019 18:10, Stephen Boyd wrote:
> This function returns an error if a child irqchip calls
> irq_chip_set_wake_parent() but its parent irqchip has the
> IRQCHIP_SKIP_SET_WAKE flag set. Let's return 0 for success here instead
> because there isn't anything to do.
> This keeps the behavior consistent with how set_irq_wake_real() is
> implemented. That function returns 0 when the irqchip has the
> IRQCHIP_SKIP_SET_WAKE flag set. It doesn't attempt to walk the chain of
> parents and set irq wake on any chips that don't have the flag set
> either. If the intent is to call the .irq_set_wake() callback of the
> parent irqchip, then we expect irqchip implementations to omit the
> IRQCHIP_SKIP_SET_WAKE flag and implement an .irq_set_wake() function
> that calls irq_chip_set_wake_parent().
> This fixes a problem on my Qualcomm sdm845 device where I can't set wake
> on any GPIO interrupts after I apply work in progress wakeup irq patches
> to the GPIO driver. The chain of chips looks like this:
>  ARM GIC (skip) -> QCOM PDC (skip) -> QCOM GPIO

nit: the parenting chain is actually built the other way around (we
don't express the 'child' relationship). This doesn't change anything to
the patch, but would make the reasoning a but easier to understand.

> The GPIO controller is a child of the QCOM PDC irqchip which is a child
> of the ARM GIC irqchip. The QCOM PDC irqchip has the
> IRQCHIP_SKIP_SET_WAKE flag set, and so does the grandparent ARM GIC.
> The GPIO driver doesn't know if the parent needs to set wake or not, so
> it unconditionally calls irq_chip_set_wake_parent() causing this
> function to return a failure because the parent irqchip (PDC) doesn't
> have the .irq_set_wake() callback set. Returning 0 instead makes
> everything work and irqs from the GPIO controller can be configured for
> wakeup.
> Cc: Lina Iyer <>
> Cc: Marc Zyngier <>
> Signed-off-by: Stephen Boyd <>

Fixes: 08b55e2a9208e ("genirq: Add irqchip_set_wake_parent")
Acked-by: Marc Zyngier <>


Jazz is not dead. It just smells funny...

linux-arm-kernel mailing list

  reply index

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-25 18:10 Stephen Boyd
2019-03-26 11:11 ` Marc Zyngier [this message]
2019-03-26 16:58   ` Stephen Boyd

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \ \ \ \ \ \ \ \ \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-ARM-Kernel Archive on

Archives are clonable:
	git clone --mirror linux-arm-kernel/git/0.git
	git clone --mirror linux-arm-kernel/git/1.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-arm-kernel linux-arm-kernel/ \
	public-inbox-index linux-arm-kernel

Example config snippet for mirrors

Newsgroup available over NNTP:

AGPL code for this site: git clone