Re: [PATCH v2 02/13] dt-bindings: display: msm: Document the Nord DiplayPort controller

[Krzysztof Kozlowski <krzk@kernel.org>]

On 21/10/2026 13:16, Nabige Aala wrote:
> 
> On 10/13/2026 2:18 PM, Krzysztof Kozlowski wrote:
>> On Tue, Oct 13, 2026 at 09:44:15AM +0200, Krzysztof Kozlowski wrote:
>>> On Mon, Oct 12, 2026 at 07:02:12PM +0530, Nabige Aala wrote:
>>>> From: Mahadevan P <mahadevan.p@oss.qualcomm.com>
>>>>
>>>> Nord uses MDSS 12.1 with two independent DP controller instances,
>>>> each exposing two DP cores at new IO offsets. None of the existing
>>>> compatibles match this layout, so add qcom,nord-dp.
>>>>
>>>> Signed-off-by: Mahadevan P <mahadevan.p@oss.qualcomm.com>
>>>> Signed-off-by: Nabige Aala <nabige.aala@oss.qualcomm.com>
>>> Do I understand correctly:
>>> Device is fully compatible with qcom,sa8775p-dp, but a simple to fix
>>> driver limitation is preventing compatibility?
>>>
>>> If so, let's fix the driver - just add more addresses to the
>>> msm_dp_desc_sa8775p array?
>> Or it does not matter, because top-level MDSS anyway cannot use
>> compatibility?
> 
> For MDSS0, the DP register offsets are same to those used on SA8775P. 
> However, the MDSS1 DP register offsets differ from SA8775P, and Nord 
> also utilizes a different MDSS instance. Because of these differences, 
> we introduced a separate compatible string for Nord.
> 
> Are you suggesting that Nord should reuse the "msm_dp_desc_sa8775p"?  
> This would also pollute the sa8775p's desc table.

What are the differences? Only registers, so no pollution. You just need
them to match IDs.

Best regards,
Krzysztof