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

[Jonathan Cameron <jic23@kernel.org>]

On Tue, 28 Apr 2026 09:38:47 +0100
Salah Triki <salah.triki@gmail.com> wrote:

> 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.
> 
Maybe Crt has the hardware to test. For now I'll assume this is not
going anywhere wrt to tracking in patchwork.

> Best regards,
> --
> Salah Triki