El Mon, Sep 12, 2016 at 06:18:31PM -0700 Matthias Kaehlcke ha dit:
> El Tue, Sep 13, 2016 at 12:57:58AM +0100 Mark Brown ha dit:
>
> > On Mon, Sep 12, 2016 at 04:18:51PM -0700, Matthias Kaehlcke wrote:
> > > El Mon, Sep 12, 2016 at 07:32:30PM +0100 Mark Brown ha dit:
> > > > On Tue, Sep 06, 2016 at 12:03:15PM -0700, Matthias Kaehlcke wrote:
...
> > > > Why were the gotos there?
> >
> > > Not sure how to interpret your question. Would you prefer no to use
> > > gotos, should the notification be skipped in case the voltage is not
> > > changed, do you expect a comment, ...?
> >
> > I mean I couldn't tell why a goto was a good idea for what seemed like
> > perfectly normal conditional logic. Either I couldn't tell because it's
> > not a good idea or it is a good idea but should be clearer in some way
> > but since I didn't really understand what the purpose of doing the gotos
> > was I can't say for sure either way.
>
> The main purpose is to avoid deeply nested code branches.
>
> Without gotos I think we'd end up with something like this:
>
> static int _regulator_do_set_voltage(struct regulator_dev *rdev,
> int min_uV, int max_uV)
> {
> ...
> if (ret == 0 && !rdev->constraints->ramp_disable) {
> if (rdev->desc->ops->set_voltage_time_sel) {
> if (old_selector >= 0 && old_selector != selector)
> rdev->desc->ops->set_voltage_time_sel(rdev,
> old_selector, selector);
> } else {
> if (old_uV != new_uV) {
> if (rdev->desc->ops->set_voltage_time)
> delay =
> rdev->desc->ops->set_voltage_time(rdev, old_uV, new_uV);
> else
> delay =
> _regulator_set_voltage_time(rdev, old_uV, new_uV);
> }
> }
>
> // delay
> }
> }
>
> I can change the patch accordingly if this is preferred.
The above improves a bit when a local ops variable is used instead of
rdev->desc->ops. With that it looks bearable and probably better than
the goto version.
