Re: gpio-pca953x: Unhandled interrupts with PCAL9555A

[Linus Walleij <linus.walleij@xxxxxxxxxx>]

On Mon, Jul 13, 2015 at 12:51 AM, Clemens Gruber
<clemens.gruber@xxxxxxxxxxxx> wrote:

> I noticed the following issue after 100001 interrupts occured on the
> pca-953x interrupt-controller driver used with a PCAL9555A chip. Its
> INT output is connected to a GPIO line of a Freescale i.MX6Q SoC.
>
> irq 47: nobody cared (try booting with the "irqpoll" option)
> [  508.320093] CPU: 0 PID: 0 Comm: swapper/0 Not tainted
> 4.2.0-rc1-00197-g3b9efb0 #92
> [  508.327669] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
> [  508.334237] [<80016cac>] (unwind_backtrace) from
> [<80013494>](show_stack+0x10/0x14)
> [  508.342006] [<80013494>] (show_stack) from
> [<80534e88>](dump_stack+0x84/0xc4)
> [  508.349251] [<80534e88>] (dump_stack) from
> [<800816cc>](__report_bad_irq+0x28/0xc4)
> [  508.357008] [<800816cc>] (__report_bad_irq) from
> [<80081c68>](note_interrupt+0x264/0x2b4)
> [  508.365288] [<80081c68>] (note_interrupt) from
> [<8007f338>](handle_irq_event_percpu+0xd0/0x138)
> [  508.374088] [<8007f338>] (handle_irq_event_percpu) from
> [<8007f3e0>](handle_irq_event+0x40/0x64)
> [  508.382973] [<8007f3e0>] (handle_irq_event) from
> [<800823dc>](handle_level_irq+0xc8/0x148)
> [  508.391338] [<800823dc>] (handle_level_irq) from
> [<8007e928>](generic_handle_irq+0x2c/0x3c)
> [  508.399799] [<8007e928>] (generic_handle_irq) from
> [<8029ea20>](mxc_gpio_irq_handler+0x38/0xf8)
> [  508.407283] pca953x 1-0020: failed reading register
> [  508.413479] [<8029ea20>] (mxc_gpio_irq_handler) from
> [<8029eb68>](mx3_gpio_irq_handler+0x88/0xe8)
> [  508.422451] [<8029eb68>] (mx3_gpio_irq_handler) from
> [<8007e928>](generic_handle_irq+0x2c/0x3c)
> [  508.431250] [<8007e928>] (generic_handle_irq) from
> [<8007ec20>](__handle_domain_irq+0x7c/0xec)
> [  508.439962] [<8007ec20>] (__handle_domain_irq) from
> [<800094ac>](gic_handle_irq+0x24/0x5c)
> [  508.448327] [<800094ac>] (gic_handle_irq) from
> [<80014084>](__irq_svc+0x44/0x7c)
> [  508.455817] Exception stack(0x80733f20 to 0x80733f68)
> [  508.460882] 3f20: 00000001 00000001 00000000 80737a30 00000000 bf7a0850
> c5ed8476 00000076
> [  508.469071] 3f40: c5c85253 00000076 00000000 807345f0 00000000 80733f68
> 80071d40 8039b9bc
> [  508.477254] 3f60: 200c0013 ffffffff
> [  508.480763] [<80014084>] (__irq_svc) from [<8039b9bc>]
> (cpuidle_enter_state+0x12c/0x264)
> [  508.488872] [<8039b9bc>] (cpuidle_enter_state) from [<8006cbe4>]
> (cpu_startup_entry+0x194/0x284)
> [  508.497678] [<8006cbe4>] (cpu_startup_entry) from [<806f5c94>]
> (start_kernel+0x3a4/0x3c4)
> [  508.505862] handlers:
> [  508.508148] [<8007f404>] irq_default_primary_handler threaded [<8029f2f0>]
> pca953x_irq_handler
> [  508.516812] Disabling IRQ #47
>
> Did any of you experience this type of issue before?
>
> In my patch [1] from last week, I added an option to unmask the interrupts on
> the PCAL9555A where they are masked by default. But when I do and if I then
> try to trigger as many as possible, they seem not to be handled correctly by
> the driver.
>
> In the devicetree I specify:
>
> gpioexp_stat_a: pcal9555a@20 {
>    compatible = "nxp,pcal9555a";
>    reg = <0x20>;
>    gpio-controller;
>    #gpio-cells = <2>;
>    interrupt-controller;
>    #interrupt-cells = <2>;
>    interrupt-parent = <&gpio1>;
>    interrupts = <20 IRQ_TYPE_EDGE_FALLING>;
>    nxp,intr-mask = <0x0000>; /* Do not mask the interrupts */
> };
>
> Both the PCA9555 [2] and the PCAL9555A [3] clear the interrupt if we read from
> the input port register.
> So apart from the PCAL9555A having interrupt mask registers which are set to 1
> upon power-on and then cleared by the changes introduced in my patch, it should
> not behave differently than the PCA9555.
>
> As the PCAL9555A also has interrupt status registers it would be possible to use
> them to find out which line triggered the interrupt, instead of relying on the
> previously read input values (as it is done now in pca953x_irq_pending).
> But the latter should work both on the PCA9555 and on the PCAL9555A, right?
>
> Am I missing something?
>
> Regards,
> Clemens
>
> [1]: https://patchwork.ozlabs.org/patch/492586/
> [2]: http://www.nxp.com/documents/data_sheet/PCA9555.pdf
> [3]: http://www.nxp.com/documents/data_sheet/PCAL9555A.pdf

You need to mail the driver maintainers and/or people that were working
on it recently. None of the maintainers have this hardware.

Use git log drivers/gpio-pca953x.c

It seems Grygorii has a patch for this (to my untrained eye) that is
merged for fixes, subject "gpio: pca953x: fix nested irqs rescheduling"

Yours,
Linus Walleij
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