Re: [PATCH v11 2/6] dt-bindings: display/msm: dp-controller: document QCS8300 compatible

[Yongxing Mou <yongxing.mou@oss.qualcomm.com>]

On 9/5/2025 4:25 PM, Krzysztof Kozlowski wrote:
> On Fri, Sep 05, 2025 at 10:50:33AM +0800, Yongxing Mou wrote:
>>
>>
>> On 9/4/2025 9:43 PM, Dmitry Baryshkov wrote:
>>> On Thu, Sep 04, 2025 at 03:22:37PM +0800, Yongxing Mou wrote:
>>>> Add compatible string for the DisplayPort controller found on the
>>>> Qualcomm QCS8300 SoC.
>>>>
>>>> The Qualcomm QCS8300 platform comes with one DisplayPort controller
>>>> that supports 4 MST streams.
>>>>
>>>> Signed-off-by: Yongxing Mou <yongxing.mou@oss.qualcomm.com>
>>>> ---
>>>>    .../bindings/display/msm/dp-controller.yaml        | 22 ++++++++++++++++++++++
>>>>    1 file changed, 22 insertions(+)
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/display/msm/dp-controller.yaml b/Documentation/devicetree/bindings/display/msm/dp-controller.yaml
>>>> index aeb4e4f36044a0ff1e78ad47b867e232b21df509..ad08fd11588c45698f7e63ecc3218a749fc8ca67 100644
>>>> --- a/Documentation/devicetree/bindings/display/msm/dp-controller.yaml
>>>> +++ b/Documentation/devicetree/bindings/display/msm/dp-controller.yaml
>>>> @@ -18,6 +18,7 @@ properties:
>>>>      compatible:
>>>>        oneOf:
>>>>          - enum:
>>>> +          - qcom,qcs8300-dp
>>>
>>> Can we use fallback to qcom,sa8775p-dp instead of declaring a completely
>>> new one?
>>>
>> I think we can not use fallback to sa8775p, since we don't have DP1
>> controller for QCS8300. SA8775P actually have 4 DP controllers (now only 2
>> really used). So in the hardware, i think it is different with SA8775P and
>> we need a new one.>>             - qcom,sa8775p-dp
> 
> I don't understand how this rationale explains what Dmitry asked.
> 
> Why number of IP blocks (and this is DPx, right?) matter? Are you sure
> you understand what compatibility means? Please read the slides from
> OSSE25 or just read writing bindings.
> 
> Best regards,
> Krzysztof
> 
Sure.. I’ll discuss this further here to make sure I fully understand 
these comments.