On Tue, Jul 03, 2012 at 10:18:31PM +0800, Shawn Guo wrote:
> On Tue, Jul 03, 2012 at 02:07:47PM +0100, Mark Brown wrote:

> > No, the regulator API will stub itself out if not enabled, and if the
> > supply is fixed then a fixed voltage regulator will do the job.  We
> > shouldn't be open coding this stuff in individual users.

> Ah, yes.  But when you say "a fixed voltage regulator", you actually
> meant dummy regulator, right?

No, I really do mean a fixed voltage regulator.  Dummy regulators should
essentially never be used in production.

>  static void flexcan_transceiver_switch(const struct flexcan_priv *priv, int on)
>  {
> +       if (on)
> +               regulator_enable(priv->reg_xcvr);
> +       else
> +               regulator_disable(priv->reg_xcvr);
> +

So long as the stack guarantees that you won't get unbalanced calls to
this and...

> +       priv->reg_xcvr = devm_regulator_get(&pdev->dev, "xcvr");

...add error checking here the code should be fine, yes.