Hi Florian
> > >> + /* Clock is optional on most platforms */
> > >> + priv->clk = devm_clk_get(dev, NULL);
> > >> + if (IS_ERR(priv->clk))
> > >> + priv->clk = NULL;
> > >
> > > at least in case of EPROBE_DEFERED this isn't the expected behavior. Maybe we should better trigger on non-existing clock?
> >
> > Good point, so more like:
> >
> > if (IS_ERR(priv->clk) && PTR_ERR(priv->clk) == -ENODEV)?
>
> Unfortunately we need to return the error in all other cases. Please
> take a look at devm_usb_get_phy in dwc2 [1]. AFAIK we don't need to
> take care of ENXIO in our case.
A few subsystems have a get_optional() call, e.g.
devm_phy_optional_get(). It does not return an error when the phy is
not supposed to exist, but in all other cases, it does.
Maybe consider adding devm_clk_get_optional()?
Andrew
