2021-09-23 17:27:04

by Nikita Yushchenko

Subject: [PATCH] gpio: pca953x: do not ignore i2c errors

From: Andrey Gusakov <[email protected]>

Per gpio_chip interface, error shall be proparated to the caller.

Attempt to silent diagnostics by returning zero (as written in the
comment) is plain wrong, because the zero return can be interpreted by
the caller as the gpio value.

Signed-off-by: Andrey Gusakov <[email protected]>
Signed-off-by: Nikita Yushchenko <[email protected]>
---
drivers/gpio/gpio-pca953x.c | 11 ++---------
1 file changed, 2 insertions(+), 9 deletions(-)

diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
index f5cfc0698799..8ebf369b3ba0 100644
--- a/drivers/gpio/gpio-pca953x.c
+++ b/drivers/gpio/gpio-pca953x.c
@@ -468,15 +468,8 @@ static int pca953x_gpio_get_value(struct gpio_chip *gc, unsigned off)
mutex_lock(&chip->i2c_lock);
ret = regmap_read(chip->regmap, inreg, &reg_val);
mutex_unlock(&chip->i2c_lock);
- if (ret < 0) {
- /*
- * NOTE:
- * diagnostic already emitted; that's all we should
- * do unless gpio_*_value_cansleep() calls become different
- * from their nonsleeping siblings (and report faults).
- */
- return 0;
- }
+ if (ret < 0)
+ return ret;

return !!(reg_val & bit);
}
--
2.30.2

2021-09-29 18:46:23

by Bartosz Golaszewski

Subject: Re: [PATCH] gpio: pca953x: do not ignore i2c errors

On Thu, Sep 23, 2021 at 7:22 PM Nikita Yushchenko
<[email protected]> wrote:
>
> From: Andrey Gusakov <[email protected]>
>
> Per gpio_chip interface, error shall be proparated to the caller.
>
> Attempt to silent diagnostics by returning zero (as written in the
> comment) is plain wrong, because the zero return can be interpreted by
> the caller as the gpio value.
>
> Signed-off-by: Andrey Gusakov <[email protected]>
> Signed-off-by: Nikita Yushchenko <[email protected]>
> ---
> drivers/gpio/gpio-pca953x.c | 11 ++---------
> 1 file changed, 2 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
> index f5cfc0698799..8ebf369b3ba0 100644
> --- a/drivers/gpio/gpio-pca953x.c
> +++ b/drivers/gpio/gpio-pca953x.c
> @@ -468,15 +468,8 @@ static int pca953x_gpio_get_value(struct gpio_chip *gc, unsigned off)
> mutex_lock(&chip->i2c_lock);
> ret = regmap_read(chip->regmap, inreg, &reg_val);
> mutex_unlock(&chip->i2c_lock);
> - if (ret < 0) {
> - /*
> - * NOTE:
> - * diagnostic already emitted; that's all we should
> - * do unless gpio_*_value_cansleep() calls become different
> - * from their nonsleeping siblings (and report faults).
> - */
> - return 0;
> - }
> + if (ret < 0)
> + return ret;
>
> return !!(reg_val & bit);
> }
> --
> 2.30.2
>

Applied, thanks!

Bart