Re: [PATCH v3 02/18] of/platform: add of_platform_probe

From	Mark Brown <broonie@kernel.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH v3 02/18] of/platform: add of_platform_probe
Date	2015-09-11 12:00 +0200
Message-ID	<q7thD-6pR-9@gated-at.bofh.it> (permalink)
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On Mon, Sep 07, 2015 at 02:31:06PM +0200, Tomeu Vizoso wrote:
> On 11 August 2015 at 11:37, Tomeu Vizoso <tomeu.vizoso@collabora.com> wrote:
> > On 7 August 2015 at 14:19, Mark Brown <broonie@kernel.org> wrote:

> >> This sounds like it's going to break in the case where we have MFDs that
> >> represent their functions in DT (not a pattern I'm a fan of but it's a
> >> thing people do).  We'll walk back to the platform device for the MFD
> >> function, try to probe it and then give up.  Perhaps that's good enough
> >> anyway but it's not clear to me why we don't just try every parent we
> >> find?

> > Agreed. In the attempt at probing dependencies before a device is
> > probed, I considered that a device's parent is also a dependency and

> Actually I'm not sure how we could probe the ascendants on demand, as
> currently the parent's device lock is taken when probing so trying to
> probe a sibling from within a probe callback will cause a deadlock.

How do silbilings come into this?  There is an issue there but it's
going to happen anyway.

> AFAICS this is only needed for USB interface devices and this
> behaviour could be limited to them, but I don't like much assuming
> that no USB device will ever have a dependency on a sibling (though
> that probably won't happen ever).

I don't see the connection with USB here, sorry - my initial thought was
about MFDs?

Thread

Re: [PATCH v3 02/18] of/platform: add of_platform_probe Tomeu Vizoso <tomeu.vizoso@collabora.com> - 2015-09-07 14:40 +0200
  Re: [PATCH v3 02/18] of/platform: add of_platform_probe Mark Brown <broonie@kernel.org> - 2015-09-11 12:00 +0200
    Re: [PATCH v3 02/18] of/platform: add of_platform_probe Tomeu Vizoso <tomeu.vizoso@collabora.com> - 2015-09-11 16:10 +0200
      Re: [PATCH v3 02/18] of/platform: add of_platform_probe Mark Brown <broonie@kernel.org> - 2015-09-11 17:40 +0200
        Re: [PATCH v3 02/18] of/platform: add of_platform_probe Tomeu Vizoso <tomeu.vizoso@collabora.com> - 2015-09-15 15:10 +0200

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