Re: [PATCH] pinctrl: samsung: add irq_set_affinity() for non wake up external gpio interrupt
From: Youngmin Nam
Date: Thu Nov 23 2023 - 23:00:20 EST
On Tue, Nov 21, 2023 at 12:33:51PM -0600, Sam Protsenko wrote:
> On Sun, Nov 19, 2023 at 2:54 AM Youngmin Nam <youngmin.nam@xxxxxxxxxxx> wrote:
> >
> > To support affinity setting for non wake up external gpio interrupt,
> > we add a new irq_set_affinity callback using irq number which is in pinctrl
> > driver data.
> >
> > Before applying this patch, we couldn't change irq affinity of gpio interrupt.
> > * before
> > erd9945:/proc/irq/418 # cat smp_affinity
> > 3ff
> > erd9945:/proc/irq/418 # echo 00f > smp_affinity
> > erd9945:/proc/irq/418 # cat smp_affinity
> > 3ff
> > erd9945:/proc/irq/418 # cat /proc/interrupts
> > CPU0 CPU1 CPU2 CPU3 CPU4 CPU5 CPU6 CPU7 CPU8 CPU9
> > 418: 3631 0 0 0 0 0 0 0 0 0 gpg2 0 Edge 19100000.drmdecon
> >
> > After applying this patch, we can change irq affinity of gpio interrupt as below.
> > * after
> > erd9945:/proc/irq/418 # cat smp_affinity
> > 3ff
> > erd9945:/proc/irq/418 # echo 00f > smp_affinity
> > erd9945:/proc/irq/418 # cat smp_affinity
> > 00f
> > erd9945:/proc/irq/418 # cat /proc/interrupts
> > CPU0 CPU1 CPU2 CPU3 CPU4 CPU5 CPU6 CPU7 CPU8 CPU9
> > 418: 3893 201 181 188 0 0 0 0 0 0 gpg2 0 Edge 19100000.drmdecon
> >
>
> Suggest formatting the commit message as follows, to make it more readable:
>
> 8<-------------------------------------------------------------------------->8
> To support affinity setting for non wake up external gpio interrupt,
> add irq_set_affinity callback using irq number from pinctrl driver
> data.
>
> Before this patch, changing the irq affinity of gpio interrupt is not
> possible:
>
> # cat /proc/irq/418/smp_affinity
> 3ff
> # echo 00f > /proc/irq/418/smp_affinity
> # cat /proc/irq/418/smp_affinity
> 3ff
> # cat /proc/interrupts
> CPU0 CPU1 CPU2 CPU3 ...
> 418: 3631 0 0 0 ...
>
> With this patch applied, it's possible to change irq affinity of gpio
> interrupt:
>
> # cat /proc/irq/418/smp_affinity
> 3ff
> # echo 00f > /proc/irq/418/smp_affinity
> # cat /proc/irq/418/smp_affinity
> 00f
> # cat /proc/interrupts
> CPU0 CPU1 CPU2 CPU3 ...
> 418: 3893 201 181 188 ...
> 8<-------------------------------------------------------------------------->8
>
Thanks for your suggestion. I'll modify it.
> > Signed-off-by: Youngmin Nam <youngmin.nam@xxxxxxxxxxx>
> > ---
> > drivers/pinctrl/samsung/pinctrl-exynos.c | 14 ++++++++++++++
> > 1 file changed, 14 insertions(+)
> >
> > diff --git a/drivers/pinctrl/samsung/pinctrl-exynos.c b/drivers/pinctrl/samsung/pinctrl-exynos.c
> > index 6b58ec84e34b..5d7b788282e9 100644
> > --- a/drivers/pinctrl/samsung/pinctrl-exynos.c
> > +++ b/drivers/pinctrl/samsung/pinctrl-exynos.c
> > @@ -147,6 +147,19 @@ static int exynos_irq_set_type(struct irq_data *irqd, unsigned int type)
> > return 0;
> > }
> >
> > +static int exynos_irq_set_affinity(struct irq_data *irqd,
> > + const struct cpumask *dest, bool force)
> > +{
> > + struct samsung_pin_bank *bank = irq_data_get_irq_chip_data(irqd);
> > + struct samsung_pinctrl_drv_data *d = bank->drvdata;
> > + struct irq_data *parent = irq_get_irq_data(d->irq);
>
> I'm probably missing something, but: why not just use "irqd" parameter
> and avoid declaring "bank" and "d"? Is "d->irq" somehow different from
> "irqd"?
>
Yes, irqd->irq is different from d->irq as below.
[ 188.230707] irqd->irq is 417
[ 188.230837] d->irq is 133
We have to use d->irq(133) instead of irqd->irq(417) because d->irq has GICv3 as a IRQ chip.
To use set_affinity() call back of GICv3, d->irq is needed.
IRQ HWIRQ Type Affinity IRQ_DESC CPU0 CPU1 CPU2 CPU3 ... Chip Name
133 603 Level 0x3ff 0xffffff883b25d800 52260 0 0 0 ... GICv3 11030000.pinctrl
417 0 Edge 0xffffffff 0xffffff883b68a800 52259 0 0 0 ... gpg2 19100000.drmdecon
erd9945: # cat /proc/interrupts | grep gpg2
417: 9250 48 45 45 ... gpg2 0 Edge 19100000.drmdecon
erd9945: # cat /proc/interrupts | grep 11030000
133: 9250 48 45 45 ... GICv3 603 Level 11030000.pinctrl
> > +
> > + if (parent)
> > + return parent->chip->irq_set_affinity(parent, dest, force);
> > +
>
> Why not use irq_chip_set_affinity_parent() API?
>
> > + return -EINVAL;
>
> Maybe use something like this instead:
>
> if (!irqd->parent_data)
> return -EINVAL;
>
> return irq_chip_set_affinity_parent(irqd, dest, force);
>
> Can you please test if this code works?
>
I tested as you suggested as below.
diff --git a/drivers/pinctrl/samsung/pinctrl-exynos.c b/drivers/pinctrl/samsung/pinctrl-exynos.c
index bf8dd5e3c3d2..593320b408ce 100644
--- a/drivers/pinctrl/samsung/pinctrl-exynos.c
+++ b/drivers/pinctrl/samsung/pinctrl-exynos.c
@@ -153,14 +153,12 @@ static int exynos_irq_set_type(struct irq_data *irqd, unsigned int type)
static int exynos_irq_set_affinity(struct irq_data *irqd,
const struct cpumask *dest, bool force)
{
- struct samsung_pin_bank *bank = irq_data_get_irq_chip_data(irqd);
- struct samsung_pinctrl_drv_data *d = bank->drvdata;
- struct irq_data *parent = irq_get_irq_data(d->irq);
-
- if (parent)
- return parent->chip->irq_set_affinity(parent, dest, force);
+ if (!irqd->parent_data) {
+ pr_err("irqd->parent_data is null!!\n");
+ return -EINVAL;
+ }
- return -EINVAL;
+ return irq_chip_set_affinity_parent(irqd, dest, force);
}
[ 149.658395] irqd->parent_data is null!!
Currently, irqd->paranet_data is null.
> > +}
> > +
> > static int exynos_irq_request_resources(struct irq_data *irqd)
> > {
> > struct samsung_pin_bank *bank = irq_data_get_irq_chip_data(irqd);
> > @@ -212,6 +225,7 @@ static const struct exynos_irq_chip exynos_gpio_irq_chip __initconst = {
> > .irq_mask = exynos_irq_mask,
> > .irq_ack = exynos_irq_ack,
> > .irq_set_type = exynos_irq_set_type,
> > + .irq_set_affinity = exynos_irq_set_affinity,
>
> What happens if we just assign irq_chip_set_affinity_parent() here?
> Would it work, or Exynos case is more complicated than this?
>
Yes, I couldn't find how to use irq_chip_set_affinity_parent() directly yet.
> > .irq_request_resources = exynos_irq_request_resources,
> > .irq_release_resources = exynos_irq_release_resources,
> > },
> > --
> > 2.39.2
> >
>