Re: [PATCH v2] pinctrl: samsung: add irq_set_affinity() for non wake up external gpio interrupt

Youngmin Nam
2023-11-30T06:55:56Z

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On Wed, Nov 29, 2023 at 12:48:56PM -0600, Sam Protsenko wrote:
> On Wed, Nov 29, 2023 at 12:32 AM Youngmin Nam <youngmin.nam@samsung.com> wrote:
> > > I tried to test this patch on E850-96, and an attempt to write into
> > > smp_affinity (for some GPIO irq) also fails for me:
> > >
> > > # echo f0 > smp_affinity
> > > -bash: echo: write error: Input/output error
> > >
> > > When I add some pr_err() to exynos_irq_set_affinity(), I can't see
> > > those printed in dmesg. So I guess exynos_irq_set_affinity() doesn't
> > > get called at all. So the error probably happens before
> > > .irq_set_affinity callback gets called.
> > >
> > > Youngmin, can you please try and test this patch on E850-96? This
> > > board is already supported in upstream kernel. For example you can use
> > > "Volume Up" interrupt for the test, which is GPIO irq.
> > >
> >
> > I intened this affinity setting would work only on *Non* Wakeup External Interrupt.
> > The "Volume Up" on E850-96 board is connected with "gpa0-7" and
> > that is Wakeup External interrupt so that we can't test the callback.
> >
>
> Oh no. It was really silly mistake on my part :) But please check my
> answer below for good news.
>
> > I couldn't find out a pin for the test on E850-96 board yet.
> > We can test if there is a usage of *Non" Wake up External Interrupt of GPIO
> > on E850-96 board.
> >
> > Do you have any idea ?
> >
>
> Yep, just managed to successfully test your patch on E850-96. My
> testing procedure below might appear messy, but I didn't want to do
> any extra soldering :)
>
> Used GPG1[0] pin for testing. As you can see from schematics [1],
> GPG1[0] is connected to R196 resistor (which is not installed on the
> board).
>
> I've modified E850-96 dts file like this:
>
> 8<---------------------------------------------------------------------------->8
> gpio-keys {
> compatible = "gpio-keys";
> pinctrl-names = "default";
> - pinctrl-0 = <&key_voldown_pins &key_volup_pins>;
> + pinctrl-0 = <&key_voldown_pins &key_volup_pins &key_test_pins>;
>
> ...
>
> + test-key {
> + label = "Test Key";
> + linux,code = <KEY_RIGHTCTRL>;
> + gpios = <&gpg1 0 GPIO_ACTIVE_LOW>;
> + };
> };
>
> ...
>
> +&pinctrl_peri {
> + key_test_pins: key-test-pins {
> + samsung,pins = "gpg1-0";
> + samsung,pin-function = <EXYNOS_PIN_FUNC_EINT>;
> + samsung,pin-pud = <EXYNOS_PIN_PULL_NONE>;
> + samsung,pin-drv = <EXYNOS5420_PIN_DRV_LV1>;
> + };
> +};
> 8<---------------------------------------------------------------------------->8
>
> It appeared in /proc/interrupts as follows:
>
> 87: 2 0 0 0 0
> 0 0 0 gpg1 0 Edge Test Key
>
> Then I touched R196 resistor pads with my finger (emulating key press)
> and looked again at /proc/interrupts:
>
> 87: 444 0 0 0 0
> 0 0 0 gpg1 0 Edge Test Key
>
> Then I reconfigured smp_affinity like so:
>
> # cat /proc/irq/87/smp_affinity
> ff
> # echo f0 > /proc/irq/87/smp_affinity
> # cat /proc/irq/87/smp_affinity
> f0
>
> Then I messed with R196 resistor pads with my finger again, and
> re-checked /proc/interrupts:
>
> CPU0 CPU1 CPU2 CPU3 CPU4
> CPU5 CPU6 CPU7
> 87: 444 0 0 0 234
> 0 0 0 gpg1 0 Edge Test Key
>
> And without this patch that procedure above of course doesn't work.
>
> So as far as I'm concerned, feel free to add:
>
> Tested-by: Sam Protsenko <semen.protsenko@linaro.org>
>
> [1] https://protect2.fireeye.com/v1/url?k=d3eebafe-8c7293d4-d3ef31b1-000babe598f7-06c0db00473e1bca&q=1&e=855a917d-d0f9-49cd-8e05-7cccf44d06a8&u=https%3A%2F%2Fwww.96boards.org%2Fdocumentation%2Fconsumer%2Fe850-96b%2Fhardware-docs%2Ffiles%2Fe850-96b-schematics.pdf
>
> Thanks!
>
Thanks for your test Sam. It's really great work.
I confirmed the patch did work by following your test sequence as below.

* Before
CPU0 CPU1 CPU2 CPU3 CPU4 ...
87: 40 0 0 0 0 ... gpg1 0 Edge Test Key

* After
87: 40 0 0 0 22 ... gpg1 0 Edge Test Key

Krzysztof,
Sam and I tested this patch on e850-95 board.
Let me update commit message with test result and will update patchset.

Thanks.

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