On Sat, 16 Mar 2024 21:38:04 +0200
Andy Shevchenko <andy.shevchenko@xxxxxxxxx> wrote:
> Thu, Feb 29, 2024 at 04:10:27PM +0100, Nuno Sa kirjoitti:
> > Use the new cleanup magic for handling mutexes in IIO. This allows us to
> > greatly simplify some code paths.
>
> ...
>
> > ret = iio_scan_mask_query(indio_dev, buffer, this_attr->address);
> > if (ret < 0)
> > - goto error_ret;
> > - if (!state && ret) {
> > - ret = iio_scan_mask_clear(buffer, this_attr->address);
> > - if (ret)
> > - goto error_ret;
> > - } else if (state && !ret) {
> > + return ret;
> > +
> > + if (state && ret)
> > + return len;
>
> I would leave the original checks. It's natural pattern
>
> if (foo && !bar)
> if (!foo && bar) // or 'else if' depending on the context
>
> > + if (state)
> > ret = iio_scan_mask_set(indio_dev, buffer, this_attr->address);
> > - if (ret)
> > - goto error_ret;
> > - }
> > + else
> > + ret = iio_scan_mask_clear(buffer, this_attr->address);
> > + if (ret)
> > + return ret;
> >
> > -error_ret:
> > - mutex_unlock(&iio_dev_opaque->mlock);
> > -
> > - return ret < 0 ? ret : len;
> > + return len;
>
> ...
>
> > /* Already in desired state */
> > if (inlist == requested_state)
> > - goto done;
> > + return len;
>
> Returning error code immediately is fine, but splitting return success seems to
> me a bit too much. It is harder to follow (you really need to understand how many
> "success" variants can be).
The pattern of detecting 'nothing to do' and existing early is pretty common.
I agree that it gets dubious if there are lots of early 'success' exits, but
this one case seems reasonable to me.
Jonathan
>
> > if (requested_state)
> > ret = __iio_update_buffers(indio_dev, buffer, NULL);
> > else
> > ret = __iio_update_buffers(indio_dev, NULL, buffer);
> > + if (ret)
> > + return ret;
> >
> > -done:
> > - mutex_unlock(&iio_dev_opaque->mlock);
> > - return (ret < 0) ? ret : len;
> > + return len;
> > }
>
