Re: [PATCH v2 2/3] iio: humidity: dht11: Emit error messages for probe failures

[Jonathan Cameron <jic23@kernel.org>]

On Mon, 18 Jul 2022 22:35:31 +0200
Uwe Kleine-König <ukleinek@debian.org> wrote:

> Hello Andy,
> 
> On 7/18/22 22:27, Andy Shevchenko wrote:
> > On Mon, Jul 18, 2022 at 9:50 PM Uwe Kleine-König <ukleinek@debian.org> wrote:  
> >>
> >> There are two exit points in the driver's probe function that fail
> >> silently. From a user perspective this is unsatisfactory because the
> >> device is unusable but there is no hint in the kernel log about the
> >> actual problem which makes it unnecessarily hard to fix the problem.
> >>
> >> Make use of dev_err_probe() to emit a problem indication which also does
> >> the right thing if requesting the gpio return -EPROBE_DEFER.  
> > 
> > ...
> >   
> >> +       ret = devm_iio_device_register(dev, iio);
> >> +       if (ret < 0)  
> > 
> > Do we really need this ' < 0' part?  
> 
> Not sure, I stumbled about that when I split the patch, too. 
> devm_iio_device_register only returns a value <= 0 and I don't expect 
> dev_err_probe to behave when the error is >= 0. So adding the check at 
> least documents the expectations. But I don't have hard feelings and 
> dropping " < 0" would be fine for me, too.

Slight preference for if (ret)

J
> 
> >> +               return dev_err_probe(dev, ret, "Failed to register iio device\n");  
> 
> Best regards
> Uwe