[PATCH 3/3] hwrng: mxc-fsl - add support for Freescale RNGC

[Uwe Kleine-König]

Hello Fabio,

On Mon, Feb 29, 2016 at 08:54:19PM -0300, Fabio Estevam wrote:
> On Mon, Feb 29, 2016 at 6:38 PM, Uwe Kleine-König
> <u.kleine-koenig at pengutronix.de> wrote:
> > On Mon, Feb 29, 2016 at 06:16:50PM -0300, Fabio Estevam wrote:
> >> On Mon, Feb 29, 2016 at 12:52 PM, Steffen Trumtrar
> >> <s.trumtrar at pengutronix.de> wrote:
> >>
> >> > +       ret = clk_prepare_enable(rngc->clk);
> >> > +       if (ret)
> >> > +               return ret;
> >> > +
> >> > +       rngc->irq = platform_get_irq(pdev, 0);
> >> > +       if (!rngc->irq) {
> >> > +               dev_err(&pdev->dev, "FSL RNGC couldn't get irq\n");
> >> > +               clk_disable_unprepare(rngc->clk);
> >> > +
> >> > +               return ret;
> >>
> >> You are returning the wrong error code here:
> >>
> >> Better do like this:
> >>
> >>        rngc->irq = platform_get_irq(pdev, 0);
> >>        if (rngc->irq < 0) {
> >
> > rngc->irq is unsigned, so this is never true.
> >
> >>                dev_err(&pdev->dev, "FSL RNGC couldn't get irq\n");
> >>                clk_disable_unprepare(rngc->clk);
> >>                return rngc->irq;
> >>        }
> >
> > So here comes my better approach:
> 
> As irq is only used inside probe it can be removed from struct mxc_rngc.

Good idea.

> Or maybe like this:
> 
>          ret = platform_get_irq(pdev, 0);
>          if (ret < 0) {
>                  dev_err(&pdev->dev, "FSL RNGC couldn't get irq\n");
>                  clk_disable_unprepare(rngc->clk);
>                  return ret;
>          }

Some people think platform_get_irq returning 0 should be handled as
error.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |