Re: [PATCH 1/2] arm64: dts: qcom: qcs6490-rb3gen2-industrial-mezzanine: Add model string

[Dmitry Baryshkov]

On Mon, Mar 23, 2026 at 10:33:45PM +0530, Umang Chheda wrote:
> Hello Dmitry,
> 
> On 3/13/2026 11:23 PM, Dmitry Baryshkov wrote:
> > On Tue, Mar 10, 2026 at 02:09:58PM +0530, Umang Chheda wrote:
> >> Hello Dmitry,
> >>
> >> On 3/10/2026 2:07 AM, Dmitry Baryshkov wrote:
> >>> On Mon, Mar 09, 2026 at 05:49:35PM +0530, Umang Chheda wrote:
> >>>> The RB3 Gen2 Industrial mezzanine DT file lacks a "model" property,
> >>>> resulting in the hardware always being reported as the "Robotics RB3gen2".
> >>>> This prevents applications and user-space tooling from distinguishing
> >>>> the Industrial mezzanine Kit from other RB3Gen2 variants.
> >>>>
> >>>> To ensure consistent identification across all RB3 Gen2 mezzanines,
> >>>> add the appropriate model string.
> >>>>
> >>>> Signed-off-by: Umang Chheda <umang.chheda@xxxxxxxxxxxxxxxx>
> >>>> ---
> >>>>  .../boot/dts/qcom/qcs6490-rb3gen2-industrial-mezzanine.dtso   | 4 ++++
> >>>>  1 file changed, 4 insertions(+)
> >>>>
> >>>> diff --git a/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2-industrial-mezzanine.dtso b/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2-industrial-mezzanine.dtso
> >>>> index 619a42b5ef48..7d6e425dae89 100644
> >>>> --- a/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2-industrial-mezzanine.dtso
> >>>> +++ b/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2-industrial-mezzanine.dtso
> >>>> @@ -8,6 +8,10 @@
> >>>>  #include <dt-bindings/clock/qcom,gcc-sc7280.h>
> >>>>  #include <dt-bindings/pinctrl/qcom,pmic-gpio.h>
> >>>>
> >>>> +&{/} {
> >>>> +	model = "Qualcomm Technologies, Inc. QCS6490 RB3gen2 Industrial Mezzanine";
> >>> So, what happens if I combine Industrial and Vision mezzanines?
> >> H/W does not support to connect both Industrial and vision mezzanine at same time - only single mezzanine can be
> >>
> >> connected at a given point in time - hence probably the above scenario would never occur.
> > Industrial mezzanine has all LS and HS connectors, so it is possible to
> > stack Vision mezz on top of the industrial one.
> 
> I re-checked - from f/w side as well multiple DTSO selection is not supported - and at a single point in time only single mezz can be selected

What does this have to do with the firmware? From the Linux build system
point of view we are combining the overlay into a single
qcs6490-rb3gen2-industrial-mezzanine.dtb file.

Nothing prevents me from writing:

qcs6490-rb3gen2-multi-mezzanine-dtbs := qcs6490-rb3gen2.dtb \
		qcs6490-rb3gen2-industrial-mezzanine.dtbo \
		qcs6490-rb3gen2-vision-mezzanine.dtbo
dtb-$(CONFIG_ARCH_QCOM)        += qcs6490-rb3gen2-multi-mezzanine.dtb

> considering above point - is it okay to have this patch ? I believe it would be good to have model string in the DTSO file added.

No. A _mezzanine_ can not be a device model. It is by definition
something that you plug into the main device. Maybe creating something
new, a new kit.

Moreover, the model name is not an ABI, we should not be using it for
device identification.

> Kindly share your views

-- 
With best wishes
Dmitry