linux-kernel - Re: [PATCH] gpio: pca953x: Clear irq trigger type on irq shutdown

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Message-ID: <CACRpkdbn_8WUQ8oqn2+M6KpEEogLTMMqbJrp-d2=HEkjJ-XtDQ@mail.gmail.com>
Date:   Wed, 16 May 2018 14:51:16 +0200
From:   Linus Walleij <linus.walleij@...aro.org>
To:     Grigoryev Denis <grigoryev@...twel.ru>,
        "H. Nikolaus Schaller" <hns@...delico.com>,
        Sergei Shtylyov <sergei.shtylyov@...entembedded.com>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Steve Longerbeam <slongerbeam@...il.com>
Cc:     "linux-gpio@...r.kernel.org" <linux-gpio@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] gpio: pca953x: Clear irq trigger type on irq shutdown

On Fri, May 4, 2018 at 6:53 PM, Grigoryev Denis <grigoryev@...twel.ru> wrote:

> The driver stores the result of irq_set_type() in the internal variables
> irq_trig_raise and irq_trig_fall, which later are used to determine
> the GPIOs that must be re-configured as input. These variables retain their
> value between gpiolib's  export / unexport, resulting in an incorrect
> state in some cases. The corresponding bits in the variables
> irq_trig_raise and irq_trig_fall should be cleared in irq_shutdown().
>
> Signed-off-by: Denis Grigoryev <grigoryev@...twel.ru>
> ---
>  drivers/gpio/gpio-pca953x.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
>
> diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
> index d2ead4b..b41be8c 100644
> --- a/drivers/gpio/gpio-pca953x.c
> +++ b/drivers/gpio/gpio-pca953x.c
> @@ -522,6 +522,15 @@ static int pca953x_irq_set_type(struct irq_data *d, unsigned int type)
>         return 0;
>  }
>
> +static void pca953x_irq_shutdown(struct irq_data *d)
> +{
> +       struct pca953x_chip *chip = irq_data_get_irq_chip_data(d);
> +       u8 mask = 1 << (d->hwirq % BANK_SZ);
> +
> +       chip->irq_trig_raise[d->hwirq / BANK_SZ] &= ~mask;
> +       chip->irq_trig_fall[d->hwirq / BANK_SZ] &= ~mask;
> +}
> +
>  static struct irq_chip pca953x_irq_chip = {
>         .name                   = "pca953x",
>         .irq_mask               = pca953x_irq_mask,
> @@ -529,6 +538,7 @@ static struct irq_chip pca953x_irq_chip = {
>         .irq_bus_lock           = pca953x_irq_bus_lock,
>         .irq_bus_sync_unlock    = pca953x_irq_bus_sync_unlock,
>         .irq_set_type           = pca953x_irq_set_type,
> +       .irq_shutdown           = pca953x_irq_shutdown,
>  };

This driver has a big set of users, so putting some maintainers
in the loop so we can get some patch review.

Yours,
Linus Walleij