Re: [PATCH 3/4] iio: backend: make use of dev_errp_probe()

[Andy Shevchenko]

On Thu, Apr 04, 2024 at 04:58:27PM +0200, Nuno Sá wrote:
> On Thu, 2024-04-04 at 15:23 +0300, Andy Shevchenko wrote:
> > On Thu, Apr 04, 2024 at 01:06:25PM +0200, Nuno Sa wrote:
> > > Using dev_errp_probe() to simplify the code.

..

> > > +	if (IS_ERR(fwnode))
> > > +		return dev_errp_probe(dev, PTR_ERR(fwnode),
> > > +				      "Cannot get Firmware reference\n");
> > 
> > ERR_CAST() seems quite good candidate to have here.
> > 
> > 		return dev_errp_probe(dev, fwnode, "Cannot get Firmware
> > reference\n");
> > 
> > (Assuming dev_errp_probe() magically understands that, note you may have it as
> >  a macro and distinguish parameter type with _Generic() or so and behave
> >  differently: ERR_PTR() vs. ERR_CAST(), see acpi_dev_hid_uid_match()
> >  implementation, but also keep in mind that it doesn't distinguish NULL/0,
> > there
> >  is a patch available in the mailing list to fix that, though.)
> 
> Do we care that much for going with that trouble?

I don't think we do. We are not supposed to be called with ret == 0/NULL.
That's why I pointed out to the current version.

> I understand like this we go
> PTR_ERR() to then comeback to ERR_PTR() but this for probe() which is not a
> fastpath. So perhaps we could just keep it simple?

It's not about performance, it's about readability. See the difference between
yours and mine.

-- 
With Best Regards,
Andy Shevchenko