Messages in this thread | | | From | Rob Herring <> | Date | Tue, 12 Apr 2016 13:31:23 -0500 | Subject | Re: [PATCH 5/5] DT: arm,gic-v3: Documment PPI partition support |
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On Tue, Apr 12, 2016 at 11:42 AM, Marc Zyngier <marc.zyngier@arm.com> wrote: > Hi Rob, > > On 12/04/16 17:29, Rob Herring wrote: >> On Mon, Apr 11, 2016 at 09:57:55AM +0100, Marc Zyngier wrote: >>> Add a decription of the PPI partitioning support. >>> >>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> >>> --- >>> .../bindings/interrupt-controller/arm,gic-v3.txt | 34 ++++++++++++++++++++-- >>> 1 file changed, 32 insertions(+), 2 deletions(-) >>> >>> diff --git a/Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt b/Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt >>> index 007a5b4..4c29cda 100644 >>> --- a/Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt >>> +++ b/Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt >>> @@ -11,6 +11,8 @@ Main node required properties: >>> - interrupt-controller : Identifies the node as an interrupt controller >>> - #interrupt-cells : Specifies the number of cells needed to encode an >>> interrupt source. Must be a single cell with a value of at least 3. >>> + If the system requires describing PPI affinity, then the value must >>> + be at least 4. >> >> You're winning for cell count... > > Yeah, it feels like we aim at making people's life difficult... > >> One alternative that would save adding a cell and keep it contained >> within would be just list the affinities in the GIC node in the form of >> '<PPI#> <count> <cpu phandles>': >> >> ppi-affinity = <1 2 &cpu2 &cpu3>, >> <5 1 &cpu4>, >> ... > > But how would that work if you have two sets of CPUs (set-1=[cpu0, > cpu1]; set-2=[cpu2, cpu3]), and for the same PPI, device A is connected > to set-1 and device-B is connected to set-2?
Oh right. Need to take those h/w designers out back...
> You need a way to distinguish these two interrupts and so far, the only > way I've found is to reference the affinity in the interrupt specifier. > > That being said, I'm definitely open to suggestions on how to describe > this in a better way.
In that case, I think it looks fine.
Acked-by: Rob Herring <robh@kernel.org>
Rob
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