Re: [PATCH v2] staging: iio: adc: ad7816: Use devm_gpiod_get_optional() for busy GPIO

[Andy Shevchenko]

On Wed, Jun 03, 2026 at 01:20:08PM +0300, Dan Carpenter wrote:
> On Wed, Jun 03, 2026 at 12:26:11PM +0300, Andy Shevchenko wrote:
> > On Wed, Jun 03, 2026 at 12:33:33PM +0000, Taha Narimani wrote:

...

> > > -	if (chip->id == ID_AD7817) {
> > > +	if (chip->busy_pin) {
> > 
> > If we get GPIO optional, this check wouldn't be necessary anymore as the below
> > should return 0 IIRC in this case.
> 
> No, it's still necessary.  It can be NULL because of the CONFIG_
> in which case, sure, gpiod_get_value() is a no-op.  But it can
> also be NULL because of the device tree and in that case we need
> the check to avoid a NULL pointer dereference.

Can you elaborate on the latter more? I fail to see that.
What I see is that the function either implemented or not is NULL-aware.

> > >  		while (gpiod_get_value(chip->busy_pin))
> > >  			cpu_relax();
> > >  	}

-- 
With Best Regards,
Andy Shevchenko