Re: [PATCH v6 13/52] dt-bindings: memory: tegra124: emc: Document new interconnect property

Dmitry Osipenko
2020-10-27T19:22:49Z

27.10.2020 13:25, Krzysztof Kozlowski пишет:
> On Mon, Oct 26, 2020 at 01:16:56AM +0300, Dmitry Osipenko wrote:
>> External memory controller is interconnected with memory controller and
>> with external memory. Document new interconnect property which turns
>> External Memory Controller into interconnect provider.
>>
>> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
>> ---
>> .../bindings/memory-controllers/nvidia,tegra124-emc.yaml | 7 +++++++
>> 1 file changed, 7 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra124-emc.yaml b/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra124-emc.yaml
>> index 278549f9e051..ac00832ceac1 100644
>> --- a/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra124-emc.yaml
>> +++ b/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra124-emc.yaml
>> @@ -29,6 +29,9 @@ properties:
>> items:
>> - const: emc
>>
>> + "#interconnect-cells":
>> + const: 0
>> +
>> nvidia,memory-controller:
>> $ref: /schemas/types.yaml#/definitions/phandle
>> description:
>> @@ -327,6 +330,7 @@ required:
>> - clocks
>> - clock-names
>> - nvidia,memory-controller
>> + - "#interconnect-cells"
>
> Another required property, what about all existing users of this binding?

EMC/devfreq drivers check presence of the new properties and ask users
to upgrade the DT. The kernel will continue to work fine using older
DTBs, but devfreq driver won't load.

>> additionalProperties: false
>>
>> @@ -345,6 +349,7 @@ examples:
>>
>> #iommu-cells = <1>;
>> #reset-cells = <1>;
>> + #interconnect-cells = <1>;
>
> You meant '0'?

'1' is for the "mc" node in the example (not "emc" node).

Anyways, I'll move this hunk to the previous patch in order to fix the
kernel bot warning.