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From:   Daniel Scally <djrscally@gmail.com>
Date:   Sat, 31 Jul 2021 22:36:14 +0100
Message-ID: <CAFLoDVHB0ywv6LYXXUM26KHB8spp3phkPGADXqhps6Z0cre0QA@mail.gmail.com>
Subject: Re: [PATCH 1/2] device property: Check fwnode->secondary in fwnode_graph_get_next_endpoint()
To:     Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc:     Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Laurent Pinchart <laurent.pinchart@ideasonboard.com>
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On Fri, Jul 30, 2021 at 12:34 PM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
>
> On Fri, Jul 23, 2021 at 02:04:59PM +0100, Daniel Scally wrote:
> >
> > On 23/07/2021 13:32, Andy Shevchenko wrote:
> > > On Thu, Jul 22, 2021 at 09:19:28PM +0100, Daniel Scally wrote:
> > >> Sensor drivers often check for an endpoint to make sure that they're
> > >> connected to a consuming device like a CIO2 during .probe(). Some of
> > >> those endpoints might be in the form of software_nodes assigned as
> > >> a secondary to the device's fwnode_handle. Account for this possibility
> > >> in fwnode_graph_get_next_endpoint() to avoid having to do it in the
> > >> sensor drivers themselves.
> > > ...
> > >
> > >> +  ep = fwnode_call_ptr_op(parent, graph_get_next_endpoint, prev);
> > >> +
> > >> +  if (IS_ERR_OR_NULL(ep) && !IS_ERR_OR_NULL(parent) &&
> > >> +      !IS_ERR_OR_NULL(parent->secondary))
> > > Nit-pick, I would put it like:
> > >
> > >     if (!IS_ERR_OR_NULL(parent->secondary) && !IS_ERR_OR_NULL(parent) &&
> > >         IS_ERR_OR_NULL(ep))
> > >
> > > or
> > >
> > >     if (IS_ERR_OR_NULL(ep) &&
> > >         !IS_ERR_OR_NULL(parent->secondary) && !IS_ERR_OR_NULL(parent))
> > >
> > > for the sake of logical split.
> >
> >
> > OK; I'll do the second one, feel like it's better to have ep as the
> > first check.
>
> Fine, but also I have just noticed that parent should be checked before
> parent->secondary.
>
> Something like this
>
>         if (IS_ERR_OR_NULL(ep) &&
>             !IS_ERR_OR_NULL(parent) && IS_ERR_OR_NULL(parent->secondary))
>
> > >> +          ep = fwnode_graph_get_next_endpoint(parent->secondary, NULL);

Yes, no problem. I'll send a v2 when I can, It will likely be another
week or so though, my computer's in a cardboard box.

>
> --
> With Best Regards,
> Andy Shevchenko
>
>