Re: [PATCH] iio: mlx90614: fix missing GPIO direction return value checks

Salah Triki
2026-04-28T08:38:53Z

On Tue, Apr 28, 2026 at 11:00:04AM +0300, Andy Shevchenko wrote:
> On Mon, Apr 27, 2026 at 10:58:00PM +0100, Salah Triki wrote:
> > The functions gpiod_direction_output() and gpiod_direction_input() can
> > fail, but their return values were previously ignored.
> >
> > If an error occurs during the GPIO configuration, the function should
> > abort the wake-up sequence and return the error code. More importantly,
> > failing to check these values could lead to the I2C bus remaining
> > locked if an error occurs after i2c_lock_bus() is called.
> >
> > Add return value checks and ensure the I2C bus is properly unlocked
> > via a goto label in case of failure.
>
> ...
>
> > - gpiod_direction_output(data->wakeup_gpio, 0);
> > +
> > + ret = gpiod_direction_output(data->wakeup_gpio, 0);
> > + if (ret)
> > + goto out_unlock;
> > +
> > msleep(chip_info->wakeup_delay_ms);
> > - gpiod_direction_input(data->wakeup_gpio);
> > +
> > + ret = gpiod_direction_input(data->wakeup_gpio);
> > + if (ret)
> > + goto out_unlock;
>
> While technically it sounds correct, the potential problem here is that you may
> fail this in case CONFIG_GPIOLIB=n. Is this GPIO optional?
> What may happen if GPIO is not optional, but for some reason setting it fails?
>
> TL;DR:
> I am not sure about this patch. At least I'm not comfortable to take it without
> testing on real HW.
>
> --
> With Best Regards,
> Andy Shevchenko
>
>

Thank you for your feedback. Since I don't have the physical hardware to
perform the necessary tests and ensure there are no regressions, I agree
that it is safer to drop this patch. I don't want to risk breaking the
driver for a minor cleanup.

Best regards,
--
Salah Triki