Re: [PATCH v2 5/5] dt-bindings: perf: Add compatible for Arm DSU-110

[Suzuki K Poulose <suzuki.poulose@arm.com>]

On 14/12/2021 14:59, Robin Murphy wrote:
> On 2021-12-14 14:42, Suzuki K Poulose wrote:
>> On 14/12/2021 14:16, Robin Murphy wrote:
>>> DSU-110 is the newest and shiniest for Armv9. Its programmer's model is
>>> largely identical to the previous generation of DSUs, so we can treat it
>>> as compatible, but it does have a a handful of extra IMP-DEF PMU events
>>> to call its own. Thanks to the new notion of core complexes, the maximum
>>> number of supported CPUs goes up as well.
>>>
>>> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
>>> ---
>>>
>>> v2: Also make it complete and valid
>>>
>>>   Documentation/devicetree/bindings/perf/arm,dsu-pmu.yaml | 8 ++++++--
>>>   1 file changed, 6 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/Documentation/devicetree/bindings/perf/arm,dsu-pmu.yaml 
>>> b/Documentation/devicetree/bindings/perf/arm,dsu-pmu.yaml
>>> index 09ddeb6a3ccc..7f31bcecedb5 100644
>>> --- a/Documentation/devicetree/bindings/perf/arm,dsu-pmu.yaml
>>> +++ b/Documentation/devicetree/bindings/perf/arm,dsu-pmu.yaml
>>> @@ -21,7 +21,11 @@ description:
>>>   properties:
>>>     compatible:
>>> -    const: arm,dsu-pmu
>>> +    oneOf:
>>> +      - const: arm,dsu-pmu
>>> +      - items:
>>> +          - const: arm,dsu-110-pmu
>>> +          - const: arm,dsu-pmu
>>
>> Couldn't this be :
>>
>>      compatible:
>>        oneOf:
>>          - const: arm,dsu-110-pmu
>>          - const: arm,dsu-pmu
>>
>> Otherwise, looks good to me.
> 
> My intent here was for the new case to use both strings and thus still 
> permit a less-specific match to the original one (hence why there's no 
> change to the actual driver included here). It's a true "compatible" in 
> the sense that you can run the thing with the existing driver as if it's 
> a 1st-gen DSU and get the expected results - at least that's the 
> conclusion I drew from a side-by-side comparison of the TRMs, and the 
> folks testing FPGAs haven't complained since I told them to try it 
> months ago :)

Ah, right. I should have guessed it from the lack of update to the driver.

Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com>