[PATCH 3/4] dt-bindings: Update domain-idle-state binding to use correct compatibles

Rob Herring robh at kernel.org
Sun Oct 30 19:50:53 PDT 2016


On Wed, Oct 26, 2016 at 09:57:35AM +0100, Sudeep Holla wrote:
> 
> 
> On 25/10/16 21:49, Kevin Hilman wrote:
> > Lina Iyer <lina.iyer at linaro.org> writes:
> > 
> > > Update domain-idle-state binding to use "domain-idle-state" compatible
> > > from Documentation/devicetree/bindings/arm/idle-states.txt.
> > > 
> > > Cc: <devicetree at vger.kernel.org>
> > > Cc: Rob Herring <robh at kernel.org>
> > > Suggested-by: Sudeep Holla <sudeep.holla at arm.com>
> > > Signed-off-by: Lina Iyer <lina.iyer at linaro.org>
> > > ---
> > >  Documentation/devicetree/bindings/power/power_domain.txt | 9 +++++----
> > >  1 file changed, 5 insertions(+), 4 deletions(-)
> > 
> > With no current users for this, I don't see the point of adding a
> > compatible now.
> > 
> > IMO, this should wait and be added with the identified user we can
> > discuss it then.
> > 
> 
> No, IMO it needs to be used for the proposed SoC idle/genpd solution.
> 
> I understand the nodes that are "arm,idle-state" compatible can be used
> for this new SoC hierarchical idle management, but it was never defined
> for that use originally. So this new feature must be advertised by the
> firmware with the presence of "domain-idle-state".
> 
> Yes we might have other ways to detect that but I have already seen that
> broken on the reference platform, so we need alternate/DT way to specify
> that.
> 
> Not all existing "arm,idle-state" compatible nodes will be capable of
> supporting this new SoC idle feature. It's just better and safer for a
> new feature getting added that relies on DT to have a new compatible.

Or perhaps you should describe something new rather than trying to 
graft in what's there. This combination of compatible strings looks a 
bit odd to me. Though, I've not really spent much time thinking about 
this.

Rob



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