Re: [RESEND PATCH 1/2] dt-bindings: dma: Add reg-names to nvidia,tegra210-adma

[Krzysztof Kozlowski <krzk@kernel.org>]

On 22/05/2024 07:35, Sameer Pujar wrote:
> 
> 
> On 21-05-2024 17:23, Krzysztof Kozlowski wrote:
>> On 21/05/2024 13:08, Sameer Pujar wrote:
>>> From: Mohan Kumar <mkumard@nvidia.com>
>>>
>>> For Non-Hypervisor mode, Tegra ADMA driver requires the register
>>> resource range to include both global and channel page in the reg
>>> entry. For Hypervisor more, Tegra ADMA driver requires only the
>>> channel page and global page range is not allowed for access.
>>>
>>> Add reg-names DT binding for Hypervisor mode to help driver to
>>> differentiate the config between Hypervisor and Non-Hypervisor
>>> mode of execution.
>>>
>>> Signed-off-by: Mohan Kumar <mkumard@nvidia.com>
>>> Signed-off-by: Sameer Pujar <spujar@nvidia.com>
>>> ---
>>>   .../devicetree/bindings/dma/nvidia,tegra210-adma.yaml  | 10 ++++++++++
>>>   1 file changed, 10 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/dma/nvidia,tegra210-adma.yaml b/Documentation/devicetree/bindings/dma/nvidia,tegra210-adma.yaml
>>> index 877147e95ecc..ede47f4a3eec 100644
>>> --- a/Documentation/devicetree/bindings/dma/nvidia,tegra210-adma.yaml
>>> +++ b/Documentation/devicetree/bindings/dma/nvidia,tegra210-adma.yaml
>>> @@ -29,8 +29,18 @@ properties:
>>>             - const: nvidia,tegra186-adma
>>>
>>>     reg:
>>> +    description: |
>>> +      For hypervisor mode, the address range should include a
>>> +      ADMA channel page address range, for non-hypervisor mode
>>> +      it starts with ADMA base address covering Global and Channel
>>> +      page address range.
>>>       maxItems: 1
>>>
>>> +  reg-names:
>>> +    description: only required for Hypervisor mode.
>> This does not work like that. I provide vm entry for non-hypervisor mode
>> and what? You claim it is virtualized?
>>
>> Drop property.
> 
> With 'vm' entry added for hypervisor mode, the 'reg' address range needs 
> to be updated to use channel specific region only. This is used to 
> inform driver to skip global regions which is taken care by hypervisor. 
> This is expected to be used in the scenario where Linux acts as a 
> virtual machine (VM). May be the hypervisor mode gives a different 
> impression here? Sorry, I did not understand what dropping the property 
> exactly means here.

It was imperative. Drop it. Remove it. I provided explanation why.

Also, drop unneeded |.

Best regards,
Krzysztof