* Frank Rowand <frowand.list@xxxxxxxxx> [160412 14:42]:
> On 4/12/2016 1:34 PM, Tony Lindgren wrote:
> >
> > OK thanks for the clarification. I don't see why "fail-hw-incomplete"
> > could not be set dynamically during the probe in some cases based
> > on the SoC revision detection for example. So from that point of
> > view using status with the "fail-sss" logic would make more sense.
>
> If the probe detects that the device should only be power managed
> based on the SoC revision, then it would simply be one more
> test added at the top of probe. The patch would change from:
>
> if (of_device_is_incomplete(pdev->dev.of_node)) {
>
> to:
>
> if (of_device_is_incomplete(pdev->dev.of_node) || socrev == XXX) {
>
> That code would be the same whether the property involved was
> status or something else.
Yeah that should work if we had a generic way to get the runtime
socrev somehow :) I guess the closest thing is the ARM system_rev.
> >> I would prefer to come up with a new boolean property (with a
> >> standard name that any node binding could choose to implement)
> >> that says something like "only power management is available for
> >> this node, do not attempt to use any other feature of the node".
> >
> > Heh that's going to be a long property name :) How about
> > unusable-incomplete-idle-only :)
>
> Or even pm-only. Maybe I got a little carried away with my
> verbosity. :)
That works for me unless somebody comes up with a better one.
I can only think unusable-for-io, which is no better.
> >> With that change, the bulk of your patch looks good, with
> >> minor changes:
> >>
> >> __of_device_is_available() would not need to change.
> >>
> >> __of_device_is_incomplete() would change to check the new
> >> boolean property. (And I would suggest renaming it to
> >> something that conveys it is ok to power manage the
> >> device, but do not do anything else to the device.)
> >
> > I'm fine with property too, but the runtime probe fail state
> > changes worry me a bit with that one.
>
> I don't understand what the concern is. The change I suggested
> would use exactly the same code for probe as the example patch
> you provided, but just with a slight name change for the function.
I guess I'm just wondering if using property vs status will make
things harder to change during runtime. For example, let's assume
u-boot needs to set some devices to "pm-only" state based on the
SoC revision on a board.
> > I think Rob also preferred to use the status though while we
> > chatted at ELC?
>
> That is the impression I got too. We'll have to see if I can
> convince him otherwise.
Yeah let's wait for his comments.
Tony
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