linux-kernel - Re: [PATCH v4 2/7] pinctrl: qcom: Use return value from irq_set

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Date:   Tue, 11 Aug 2020 13:06:12 -0700
From:   Doug Anderson <dianders@...omium.org>
To:     Stephen Boyd <swboyd@...omium.org>
Cc:     Maulik Shah <mkshah@...eaurora.org>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        Evan Green <evgreen@...omium.org>,
        LinusW <linus.walleij@...aro.org>, Marc Zyngier <maz@...nel.org>,
        Matthias Kaehlcke <mka@...omium.org>,
        LKML <linux-kernel@...r.kernel.org>,
        linux-arm-msm <linux-arm-msm@...r.kernel.org>,
        "open list:GPIO SUBSYSTEM" <linux-gpio@...r.kernel.org>,
        Andy Gross <agross@...nel.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Jason Cooper <jason@...edaemon.net>,
        Rajendra Nayak <rnayak@...eaurora.org>,
        Lina Iyer <ilina@...eaurora.org>,
        Srinivas Rao L <lsrao@...eaurora.org>
Subject: Re: [PATCH v4 2/7] pinctrl: qcom: Use return value from irq_set_wake call

Hi,

On Tue, Aug 11, 2020 at 12:34 PM Stephen Boyd <swboyd@...omium.org> wrote:
>
> Quoting Maulik Shah (2020-08-10 04:20:55)
> > msmgpio irqchip is not using return value of irq_set_wake call.
> > Start using it.
>
> Does this work when the irq parent isn't setup in a hierarchy? I seem to
> recall that this was written this way because sometimes
> irq_set_irq_wake() would fail for the summary irq so it was a best
> effort setting of wake on the summary line.
>
> >
> > Fixes: e35a6ae0eb3a ("pinctrl/msm: Setup GPIO chip in hierarchy")
> > Signed-off-by: Maulik Shah <mkshah@...eaurora.org>
> > Reviewed-by: Douglas Anderson <dianders@...omium.org>
> > ---
> >  drivers/pinctrl/qcom/pinctrl-msm.c | 8 +++-----
> >  1 file changed, 3 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/pinctrl/qcom/pinctrl-msm.c b/drivers/pinctrl/qcom/pinctrl-msm.c
> > index 90edf61..c264561 100644
> > --- a/drivers/pinctrl/qcom/pinctrl-msm.c
> > +++ b/drivers/pinctrl/qcom/pinctrl-msm.c
> > @@ -1077,12 +1077,10 @@ static int msm_gpio_irq_set_wake(struct irq_data *d, unsigned int on)
> >          * when TLMM is powered on. To allow that, enable the GPIO
> >          * summary line to be wakeup capable at GIC.
> >          */
> > -       if (d->parent_data)
> > -               irq_chip_set_wake_parent(d, on);
> > -
> > -       irq_set_irq_wake(pctrl->irq, on);
> > +       if (d->parent_data && test_bit(d->hwirq, pctrl->skip_wake_irqs))
> > +               return irq_chip_set_wake_parent(d, on);
>
> So this bit is probably fine.
>
> >
> > -       return 0;
> > +       return irq_set_irq_wake(pctrl->irq, on);
>
> But this one is probably not fine.

Interesting.  I wasn't aware of the history and thus assumed this was
a bug.  If Stephen is remembering correctly, please add a comment
saying that we are purposely ignoring the return value in this case.

-Doug