Re: [PATCH v3 1/3] media: dt-bindings: rockchip,vdec: Add alternative reg-names order for RK35{76,88}

[Krzysztof Kozlowski <krzk@kernel.org>]

On 25/02/2026 13:26, Krzysztof Kozlowski wrote:
> On 25/02/2026 13:19, Cristian Ciocaltea wrote:
>> With the introduction of the RK3588 SoC, and RK3576 afterwards, the
>> 'link' and 'cache' register blocks have been provided for the video
>> decoder unit in addition to the existing 'function' one, which now shows
>> up in between them (from address-based ordering point of view).
>>
>> However, the binding does not properly describe this hardware layout, as
>> the new blocks are listed after the old one.  Therefore it breaks the
>> convention expecting the unit address to indicate the first register
>> range.
>>
>> Since the binding changes have been already released and a fix would
>> bring up an ABI break, mark the current 'reg-names' listing as
>> deprecated and introduce an alternative 'link,function,cache' one.
>>
>> Additionally, drop the 'reg' description items as the order is not fixed
>> anymore, while the information they offer is not very relevant anyway.
>>
>> Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
>> ---
>>  .../devicetree/bindings/media/rockchip,vdec.yaml      | 19 ++++++++++++-------
>>  1 file changed, 12 insertions(+), 7 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/media/rockchip,vdec.yaml b/Documentation/devicetree/bindings/media/rockchip,vdec.yaml
>> index 809fda45b3bd..3f6072e8baa5 100644
>> --- a/Documentation/devicetree/bindings/media/rockchip,vdec.yaml
>> +++ b/Documentation/devicetree/bindings/media/rockchip,vdec.yaml
>> @@ -28,16 +28,21 @@ properties:
>>  
>>    reg:
>>      minItems: 1
>> -    items:
>> -      - description: The function configuration registers base
>> -      - description: The link table configuration registers base
>> -      - description: The cache configuration registers base
>> +    maxItems: 3
>>  
>>    reg-names:
>> -    items:
>> +    oneOf:
>>        - const: function
> 
> This is confusing, I think I missed that in previous patch because it
> did not leave that part or I misread the diff hunk - why do you allow
> one entry?
> 
> If the first entry is function, then all others MUST built on top, thus
> this:
> 
>> +          - const: link
>> +          - const: function
>> +          - const: cache
> 
> is not correct.
> 
> No, you don't change the orders. So again, if you have such binding,
> then you just fix the unit address leaving the binding as is.
> 

I just now checked v2 - it had this first "function" left, so I missed
that part. I would give different review at v2, so you would not waste
time. Apologies for that.

Best regards,
Krzysztof