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Date: Tue, 20 Dec 2011 01:01:09 +0000
From: Mark Brown <broonie@opensource.wolfsonmicro.com>
To: NeilBrown <neilb@suse.de>
Cc: MyungJoo Ham <myungjoo.ham@samsung.com>, linux-kernel@vger.kernel.org,
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        Morten CHRISTIANSEN <morten.christiansen@stericsson.com>
Subject: Re: [PATCH v2 0/3] introduce External Connector Class (extcon)
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On Sun, Dec 18, 2011 at 06:15:50PM +1100, NeilBrown wrote:
> On Thu, 15 Dec 2011 14:51:55 +0800 Mark Brown

> > Grant has a proposal for this which revolves around devices trying to
> > acquire their resources and returning a "please retry" error code if
> > they don't have all their dependencies.  Half the problem here is that

> A possibility I have been thinking about is to multithread do_initcalls() and
> have the various request functions (gpio_request, regulator_get, request_irq,
> etc) optionally block if the resource isn't available.

That seems to be logically the same in terms of what it actually does
but introduces concurrency which wasn't there before which means that
things could get reordered for random reasons.  That seems like it'd not
be great for robustness.

> Do we need to talk about devices that haven't been enumerated yet? or was
> that just if we wanted to create an explicit dependency graph?

You need to know about devices that aren't enumerated yet.