Re: [PATCH v14 02/14] gpio: regmap: add GPIO_REGMAP_QUIRK_SET_AFTER_DIR

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential
issue to consider:
- [Medium] gpio: regmap: unchecked gpio_regmap_set() in
  gpio_regmap_direction_output()
--

commit 5e5487072ae4c1723cfe95105497cc99bb91bff0
Author: Long Zhao <longzhao@ambarella.com>

gpio: regmap: add GPIO_REGMAP_QUIRK_SET_AFTER_DIR

This commit adds the GPIO_REGMAP_QUIRK_SET_AFTER_DIR flag to write the
output value after configuring the line direction for controllers that
ignore output writes while a line is configured as an input.

> diff --git a/drivers/gpio/gpio-regmap.c b/drivers/gpio/gpio-regmap.c
> index 51b4d69b87403..0a44deae3d01e 100644
> --- a/drivers/gpio/gpio-regmap.c
> +++ b/drivers/gpio/gpio-regmap.c

[ ... ]

> @@ -271,9 +272,17 @@ static int gpio_regmap_direction_output(struct gpio_chip *chip,
>  			return ret;
>  	}
>  
> -	gpio_regmap_set(chip, offset, value);
> +	if (!(gpio->quirks & GPIO_REGMAP_QUIRK_SET_AFTER_DIR))
> +		gpio_regmap_set(chip, offset, value);
>  
> -	return gpio_regmap_set_direction(chip, offset, true);
> +	ret = gpio_regmap_set_direction(chip, offset, true);
> +	if (ret)
> +		return ret;
> +
> +	if (gpio->quirks & GPIO_REGMAP_QUIRK_SET_AFTER_DIR)
> +		gpio_regmap_set(chip, offset, value);
> +
> +	return 0;
>  }

[Severity: Medium]
Should gpio_regmap_direction_output() check and propagate errors from
gpio_regmap_set()?

gpio_regmap_set() returns a negative errno when reg_mask_xlate() or the
regmap write fails.  Ignoring that return value in both branches either
enables the output driver with a stale value or reports success to the
caller after failing to write the requested output value.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261110-cv75-gpio-v14-0-e586aad0467a@ambarella.com?part=2