Subject: [PATCH v2 1/7] clk: Add a generic clock infrastructure

From: [email-masked] (Mark Brown)
Date: Mon, 3 Oct 2011 17:31:08 +0100

On Mon, Oct 03, 2011 at 10:24:52AM -0500, Rob Herring wrote:
> On 10/03/2011 09:25 AM, Mark Brown wrote:

> > This isn't in any way specific to clocks, right now the likely solution
> > looks to be Grant's changes for retrying probe() as new devices come on
> > line.  With that devices can return a code from their probe() which
> > tells the driver core that they couldn't get all the resources they need
> > and that it should retry the probe() if more devices come on-line.

> Except SOC clocks are initialized very early before timers are up and
> there can be a very high number of dependencies (every clock except
> fixed clocks). With the driver probe retry, retrying is the exception,
> not the rule.

> Retrying would require every caller to maintain a list of clks to
> retry. With 2 stages, you can move that into the core clock code.

They don't need to maintain a list of clocks to retry, they need to
unwind when probe() fails.  But yes.

> There are not typically a large number of board-level/driver created
> clocks, so ensuring correct register order is not really a problem. In
> cases where there is a cross-driver dependency, the probe retry is a
> good solution.

I dunno, I get the impression that some of this is due to the current
limitations of the clock API rather than due to a lack of clocks -
perhaps that's specific to the applications I look at, though.
applications