Re: [PATCH] spi/spi_s3c64xx: Move to subsys_initcall()

[Mark Brown <broonie@opensource.wolfsonmicro.com>]

On Wed, Sep 08, 2010 at 10:44:32AM -0600, Grant Likely wrote:
> On Wed, Sep 08, 2010 at 05:22:51PM +0100, Mark Brown wrote:

> > Doing dependencies could get pretty complicated, especially once you
> > handle optional dependencies ("is this missing because it didn't probe
> > yet or because it's just not there?") so it's not entirely clear to me
> > that it's worth the hassle.

> I think it might be doable.  I had a similar problem with Ethernet
> MACs and PHYs where the PHY was on a completely separate bus from the
> MAC with zero guarantees on probe order.  I had some code that made it
> simple to use a bus notifier to defer MAC initialization until the
> required phy turned up and was probed.  I eventually abandoned it
> because accessing the PHY could be deferred until .ndo_open() time.
> However, it would be easy to resurrect, and might be a reasonable
> solution.  At the very least it is worth an investigation.

If you've got stuff that'd be great - ASoC also has a deferral mechanism
implemented due to this song and dance.  Like I say, the main reason
I've never looked at it myself is that it's never been sufficiently much
of a practical problem for me to justify the effort.