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

[Nabige Aala]

On 10/21/2026 5:23 PM, Krzysztof Kozlowski wrote:
> 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@xxxxxxxxxxxxxxxx>
> > > > >
> > > > > 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@xxxxxxxxxxxxxxxx>
> > > > > Signed-off-by: Nabige Aala <nabige.aala@xxxxxxxxxxxxxxxx>
> > > > 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.

Yes, only registers are changed.

Okay, I'll update the SA8775P descriptor table to also support Nord and 
drop the "qcom,nord-dp" compatible string change.

> Best regards,
> Krzysztof