Re: [PATCH] mmc: move regulator handling to core

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

On Thu, Dec 03, 2009 at 02:32:00PM +0100, Daniel Mack wrote:
> On Thu, Dec 03, 2009 at 01:22:41PM +0000, Mark Brown wrote:
> > On Thu, Dec 03, 2009 at 02:14:23PM +0100, Daniel Mack wrote:

> > > I would expect the power to be killed when the last user stops using it.
> > > Which should result in the same effect if you only have one host, one
> > > regulator, and one user.

> > Yes, it's always fine in that case (modulo always_on and/or regulators
> > without power control). 

> Well, it didn't for me and always_on, though, due to the return values I
> described.

I mean your new code is fine.

> > This goes back to the thing about using
> > regulator_get_exclusive(), the message given was that the MMC drivers
> > really needed to be able to guarantee that the power would be removed
> > when that was requested.

> > Like I say, if there isn't a *strict* requirement but it's only
> > desirable (possibly strongly desirable) then your approach is obviously
> > preferable.

> The mmci people would need to answer that. To me, the code just looked
> like a power saving feature.

> If this driver needs it, the only tweak to my patch to let that
> particular call site use regulator_get_exclusive, and the core will
> still do the right thing. For this case, the behaviour should be exactly
> the same than it currently is, correct?

No, you'll also need to update the way the driver bootstraps the
reference count since with regulator_get_exclusive() the reference count
is initialised to 1 if the regulator is enabled when it is claimed.