Re: lm90 driver no longer working on PCs in 3.13

From: Mark Brown
Date: Sun Jan 26 2014 - 17:02:48 EST


On Sun, Jan 26, 2014 at 01:47:09PM -0800, Guenter Roeck wrote:

Please fix your mailer to word wrap within 80 columns, I've reflowed for
legibility.

> You have a solution for that in dt configurations. I don't think you
> have one for non-dt systems - you simply assume that all regulators
> are there. For dt, you even have a constraint to tell the kernel if
> regulator configurations are fully specified, and you automatically
> return success if not and if a regulator does not exist. So you know
> that there is a problem. For non-DT configurations you simply assume
> and expect that regulators are all declared. I don't think that is a
> feasible approach for non-DT systems.

To repeat the mechanism that's there for other platforms is to either
flag that they've provided full constraints or provide the supply
mappings. This has always been the case, there's nothing new here - the
only change there's been in this is that in v3.13 we refactored how
systems using DT flag that they have full constraints.

I agree that it's not going to work terribly well if neither of these
things has been done, it never has done and that's why the API has stubs
when it's disabled - they allow us to avoid a hard dependency on it in
drivers so people only need to turn it on if they're actually using it.
I'm very surprised to see anyone doing that to be honest, if you're not
using it it's just going to waste cycles and RAM.

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