Re: [PATCH v3 1/3] dt-bindings: phy: qcom,qmp: Add PCIe qcom,refclk-always-on property

Manivannan Sadhasivam
2023-12-01T06:07:35Z

On Tue, Nov 28, 2023 at 02:49:18PM +0530, Krishna Chaitanya Chundru wrote:
>
> On 11/28/2023 2:26 PM, Krzysztof Kozlowski wrote:
> > On 27/11/2023 13:13, Krishna chaitanya chundru wrote:
> > > Document qcom,refclk-always-on property which is needed in some platforms
> > > to supply refclk even in PCIe low power states.
> > >
> > > Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com>
> > > ---
> > > .../devicetree/bindings/phy/qcom,sc8280xp-qmp-pcie-phy.yaml | 7 +++++++
> > > 1 file changed, 7 insertions(+)
> > >
> > > diff --git a/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-pcie-phy.yaml b/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-pcie-phy.yaml
> > > index 2c3d6553a7ba..c747c9f35795 100644
> > > --- a/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-pcie-phy.yaml
> > > +++ b/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-pcie-phy.yaml
> > > @@ -93,6 +93,13 @@ properties:
> > > "#phy-cells":
> > > const: 0
> > > + qcom,refclk-always-on:
> > > + type: boolean
> > > + description: In some platform where PCIe switch is connected, pcie switch due to some design
> > You received a comment to use proper wrapping: 80. Please implement it.
> I will update this.
> > > + limitation fails to propage clkreq signal to the host and due to that host will not send
> > > + refclk, which results in linkdown in L1.2 or L1.1 exit initiated by EP.
> > > + This property if set keeps refclk always on even in Low power states.
> > The property name suggests that's the state of hardware - refclk is
> > always on. Description suggests you want to instruct OS to do something.
> >
> > Again, third time (once from Bjorn, once from Dmitry), rephrase property
> > name and description to describe the hardware issue. I see description
> > improved, but not the property name. Again in the end of description you
>
> Both bjorn and Dmitry gave comments to change the description only, and not
> the property name,
>
> correct if I am wrong.
>
> > say what Linux should do. Bindings do not describe Linux OS.
>
> I will remove the last line in the next patch.
>

You should name the property as, "qcom,keep-refclk-always-on"

Also, no need to stuff the binding with "why this property is required", that
info should be part of the patch description. Just describe what this property
means in binding.

- Mani

> - Krishna Chaitanya.
>
> >
> > Best regards,
> > Krzysztof
>

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