Re: [PATCH 1/2] mmc: dw_mmc: Handle late vmmc regulator with EPROBE_DEFER

Mark Brown
2013-06-07T10:24:38Z

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On Fri, Jun 07, 2013 at 12:19:58PM +0200, Tomasz Figa wrote:
> On Thursday 06 of June 2013 21:46:45 Doug Anderson wrote:

> > dw_mmc is probed. This regulator is optional, though a warning will
> > be printed if it's missing. The fact that the regulator is optional
> > means that (at the moment) it's not possible to use a regulator that
> > probes _after_ dw_mmc.

> > Fix this limitation by adding the ability to make vmmc required. If a
> > vmmc-supply is specified in the device tree we'll assume that vmmc is
> > required.

> This interesting case makes me think that regulator core should
> differentiate between regulator lookup failure due to no lookup specified
> and due to the regulator specified in lookup being unavailable, returning
> appropriate (different) error codes.

It does exactly that in so far as it can - you get -ENODEV if there's
definitely no supply and -EPROBE_DEFER otherwise.

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