On Tue, Nov 20, 2012 at 02:43:40PM +0100, Marc Kleine-Budde wrote:
> On 11/20/2012 02:40 PM, Peter Chen wrote:
> > On Tue, Nov 20, 2012 at 12:41:03PM +0100, Marc Kleine-Budde wrote:
> >> On 11/20/2012 02:33 AM, Peter Chen wrote:
> >>> On Mon, Nov 19, 2012 at 05:05:16PM +0100, Marc Kleine-Budde wrote:
> >>>>> +int ci_hdrc_otg_init(struct ci13xxx *ci)
> >>>>> +{
> >>>>> + /* Useless at current */
> >>>>> + ci->otg.set_peripheral = ci_otg_set_peripheral;
> >>>>> + ci->otg.set_host = ci_otg_set_host;
> >>>>> + if (!IS_ERR_OR_NULL(ci->transceiver))
> >>>> ^^^^^^^^^^^^^^
> >>>>
> >>>> Is considered harmful by some people. Can we test against NULL here?
> >>>
> >>> Any stories that it is harmful?
> >>
> >> Your use-case isn't but there others are:
> >> http://www.mail-archive.com/linux-omap@xxxxxxxxxxxxxxx/msg78030.html
> >
> > Thanks, marc. It said below code is error if the foo is really null.
> > if (IS_ERR_OR_NULL(foo))
> > return PTR_ERR(foo);
>
> Yes. So my next comment is nitpicking: :)
>
> > For this case, the ci->transceiver may be null or errno pointer, it
> > needs IS_ERR_OR_NULL.
>
> Yes, but you can set ci->transceiver to NULL in case of an error when
> assigning it, to avoid IS_ERR_OR_NULL here.
OK, as the chipidea/udc.c also uses this macro. I will submit a patch
to change them together later, not sure if it is necessary for everyone.
>
> Marc
>
> --
> Pengutronix e.K. | Marc Kleine-Budde |
> Industrial Linux Solutions | Phone: +49-231-2826-924 |
> Vertretung West/Dortmund | Fax: +49-5121-206917-5555 |
> Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |
>
--
Best Regards,
Peter Chen
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