linux-kernel - Re: [PATCH] driver: pca953x: avoid error message when resuming

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Date:   Mon, 7 Mar 2022 15:33:16 +0100
From:   Bartosz Golaszewski <brgl@...ev.pl>
To:     Alifer Moraes <alifer.m@...iscite.com>
Cc:     Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        eran.m@...iscite.com, Linus Walleij <linus.walleij@...aro.org>,
        "open list:GPIO SUBSYSTEM" <linux-gpio@...r.kernel.org>,
        pierluigi.p@...iscite.com,
        FrancescoFerraro <francesco.f@...iscite.com>
Subject: Re: [PATCH] driver: pca953x: avoid error message when resuming

On Mon, Mar 7, 2022 at 3:20 PM Alifer Moraes <alifer.m@...iscite.com> wrote:
>
> From: FrancescoFerraro <francesco.f@...iscite.com>
>
> Avoids the error messages "pca953x 1-0020: failed reading register"
> when resuming from suspend using gpio-key attached to pca9534.
>

The commit message should read: "gpio: pca953x: ..."

> Signed-off-by: Francesco Ferraro <francesco.f@...iscite.com>
> Signed-off-by: Alifer Moraes <alifer.m@...iscite.com>
> ---
>  drivers/gpio/gpio-pca953x.c | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
> index d2fe76f3f34f..4f35b75dcbb1 100644
> --- a/drivers/gpio/gpio-pca953x.c
> +++ b/drivers/gpio/gpio-pca953x.c
> @@ -211,6 +211,7 @@ struct pca953x_chip {
>         struct regulator *regulator;
>
>         const struct pca953x_reg_config *regs;
> +       int is_in_suspend;

Something like this is not needed because we already have
pm_runtime_status_suspended().

>  };
>
>  static int pca953x_bank_shift(struct pca953x_chip *chip)
> @@ -412,7 +413,8 @@ static int pca953x_read_regs(struct pca953x_chip *chip, int reg, unsigned long *
>
>         ret = regmap_bulk_read(chip->regmap, regaddr, value, NBANK(chip));
>         if (ret < 0) {
> -               dev_err(&chip->client->dev, "failed reading register\n");
> +               if (!chip->is_in_suspend)
> +                       dev_err(&chip->client->dev, "failed reading register\n");
>                 return ret;
>         }
>
> @@ -954,6 +956,7 @@ static int pca953x_probe(struct i2c_client *client,
>         chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
>         if (chip == NULL)
>                 return -ENOMEM;
> +       chip->is_in_suspend = 0;
>
>         pdata = dev_get_platdata(&client->dev);
>         if (pdata) {
> @@ -1161,6 +1164,8 @@ static int pca953x_suspend(struct device *dev)
>         else
>                 regulator_disable(chip->regulator);
>
> +       chip->is_in_suspend = 1;
> +
>         return 0;
>  }
>
> @@ -1189,6 +1194,8 @@ static int pca953x_resume(struct device *dev)
>                 return ret;
>         }
>
> +       chip->is_in_suspend = 0;
> +
>         return 0;
>  }
>  #endif
> --
> 2.25.1
>

Can you elaborate more on the circumstances in which you're seeing this?

Bart