[PATCH v4 4/8] dt-bindings: firmware: arm,scmi: Add atomic-threshold-us optional property

Cristian Marussi cristian.marussi at arm.com
Tue Feb 15 13:07:44 PST 2022


On Tue, Feb 15, 2022 at 03:03:52PM -0600, Rob Herring wrote:
> On Sun, Feb 13, 2022 at 07:58:28PM +0000, Cristian Marussi wrote:
> > SCMI protocols in the platform can optionally signal to the OSPM agent
> > the expected execution latency for a specific resource/operation pair.
> > 
> > Introduce an SCMI system wide optional property to describe a global time
> > threshold which can be configured on a per-platform base to determine the
> > opportunity, or not, for an SCMI command advertised to have a higher
> > latency than the threshold, to be considered for atomic operations:
> > high-latency SCMI synchronous commands should be preferably issued in the
> > usual non-atomic mode.
> > 
> > Cc: Rob Herring <robh+dt at kernel.org>
> > Cc: devicetree at vger.kernel.org
> > Signed-off-by: Cristian Marussi <cristian.marussi at arm.com>
> > ---
> > v3 --> v4
> > - renamed property to atomic-threshold-us
> > v1 --> v2
> > - rephrased the property description
> > ---
> >  .../devicetree/bindings/firmware/arm,scmi.yaml        | 11 +++++++++++
> >  1 file changed, 11 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/firmware/arm,scmi.yaml b/Documentation/devicetree/bindings/firmware/arm,scmi.yaml
> > index eae15df36eef..3ffa669b91af 100644
> > --- a/Documentation/devicetree/bindings/firmware/arm,scmi.yaml
> > +++ b/Documentation/devicetree/bindings/firmware/arm,scmi.yaml
> > @@ -81,6 +81,15 @@ properties:
> >    '#size-cells':
> >      const: 0
> >  
> > +  atomic-threshold-us:
> > +    $ref: /schemas/types.yaml#/definitions/uint32
> > +    description:
> > +      An optional time value, expressed in microseconds, representing, on this
> > +      platform, the threshold above which any SCMI command, advertised to have
> > +      an higher-than-threshold execution latency, should not be considered for
> > +      atomic mode of operation, even if requested.
> 
> > +      If left unconfigured defaults to zero.
> 
> This can be expressed as 'default: 0'.
> 

Thanks, I'll fix next V5 together with the warnings/errors fixes exposed
by your DT check bot (I had an obsoleted dtschema package indeed...)

Possibly tomorrow I'll send a v5.

Thanks,
Cristian




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