Re: [PATCH v2] arm64: dts: qcom: qcs6490-rb3gen2-industrial-mezzanine: disable WCN6750 and WPSS

[Dmitry Baryshkov]

On Thu, Mar 12, 2026 at 01:08:56PM +0800, Hangtian Zhu wrote:
> 
> 
> On 3/12/2026 11:04, Dmitry Baryshkov wrote:
> > On Wed, Mar 11, 2026 at 03:06:08PM +0800, Hangtian Zhu wrote:
> >>
> >>
> >> On 3/11/2026 12:34, Dmitry Baryshkov wrote:
> >>> On Wed, Mar 11, 2026 at 11:11:45AM +0800, Hangtian Zhu wrote:
> >>>> From: Hangtian Zhu <hangtian@xxxxxxxxxxxxxxxx>
> >>>>
> >>>> Disable WCN6750 and WPSS on industrial mezzanine. On RB3 Gen2 industrial
> >>>
> >>> You can't disable these devices on the mezzanine, they are not a part of
> >>> it.
> >>>
> >>>> mezzanine platform, pcie0 lines are moved from WCN6750 to QPS615 pcie
> >>>
> >>> PCIe0. How re they moved? What triggers the move?
> >> Please refer to: https://lore.kernel.org/all/20260305-industrial-mezzanine-pcie-v4-0-1f2c9d1344d7@xxxxxxxxxxxxxxxx/
> >> On RB3 Gen2 industrial mezzanine, WCN6750 is not connected, instead TC9563 PCIe bridge is connected to PCIe0.
> > 
> > THis doesn't answer the question, what triggers the move? Is it done
> > automatically? Is there a pin that is sourced by the carrier board?
> > Is there something else?
> It's the hardware design itself. Industrial mezzanine (should be called 'kit') is not a plugin device on top of core kit, but a non‑modular integrated device.
> Hardware redesigned QCS6490 SOM and disconnected WCN6750 from PCIe0 for this device, PCIe0 connects TC9563 PCIe bridge.

This needs to be explained in the commit message. Mention that the
resistors on SoM are soldered differently and that it's not a separate
pluggable mezzanine.

And having this in mind, this _must_ be squashed into the original
Industrial Kit / Mezzanine submission, together with all the
explanations.


> 
> > 
> >>
> >>>
> >>>> bridge. Hence disable WPSS and WCN6750 nodes for industrial mezzanine
> >>>> platform.
> >>>>
> >>>> Depends-on: https://lore.kernel.org/all/20260305-industrial-mezzanine-pcie-v4-2-1f2c9d1344d7@xxxxxxxxxxxxxxxx/
> >>>
> >>> NAK. Don't invent non-standard tags.
> >>>
> >>>>
> >>>> Signed-off-by: Hangtian Zhu <hangtian@xxxxxxxxxxxxxxxx>
> >>>> ---
> >>>>  .../dts/qcom/qcs6490-rb3gen2-industrial-mezzanine.dtso    | 8 ++++++++
> >>>>  1 file changed, 8 insertions(+)
> >>>>
> >>>
> >>
> > 
> 

-- 
With best wishes
Dmitry