Re: [PATCH v3 1/2] arm64: dts: qcom: add data-lanes and link-freuencies into dp_out endpoint

From: Dmitry Baryshkov
Date: Fri Nov 18 2022 - 06:01:28 EST


On Fri, 18 Nov 2022 at 00:50, Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx> wrote:
>
> Add both data-lanes and link-frequencies property to dp_out endpoint.

Bindings update?
Deprecate the old data-lanes property?

> Also set link-frequencies to 810000 khz at herobrine platform to have
> max link rate limited at 810000 khz (HBR3).

No. As I stated before, the link-frequencies should list all
supported frequencies (min/max in case the frequencies are
continuous).
Stating just maximum is against the property description.

>
> Signed-off-by: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx>
> ---
> arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi | 9 ++++++++-
> arch/arm64/boot/dts/qcom/sc7180.dtsi | 5 -----
> arch/arm64/boot/dts/qcom/sc7280-herobrine.dtsi | 10 +++++++++-
> arch/arm64/boot/dts/qcom/sc7280.dtsi | 5 -----
> 4 files changed, 17 insertions(+), 12 deletions(-)
>

[skipped the sc7180 here. All comments noted against sc7280 apply to
sc7180 too].

> diff --git a/arch/arm64/boot/dts/qcom/sc7280-herobrine.dtsi b/arch/arm64/boot/dts/qcom/sc7280-herobrine.dtsi
> index 93e39fc..e8fca18 100644
> --- a/arch/arm64/boot/dts/qcom/sc7280-herobrine.dtsi
> +++ b/arch/arm64/boot/dts/qcom/sc7280-herobrine.dtsi
> @@ -440,7 +440,15 @@ ap_i2c_tpm: &i2c14 {
> status = "okay";
> pinctrl-names = "default";
> pinctrl-0 = <&dp_hot_plug_det>;
> - data-lanes = <0 1>;
> + ports {
> + port@1 {
> + reg = <1>;
> + dp_out: endpoint {
> + data-lanes = <0 1>;
> + link-frequencies=<810000>;

Following the existing examples is nice. Not following them is frowned upon.

> + };
> + };
> + };

Just:

&dp_out {
data-lanes = <0 1>;
link-frequencies = /bits/ 64 <160000000 270000000 540000000 810000000>;
};

> };
>
> &mdss_mdp {
> diff --git a/arch/arm64/boot/dts/qcom/sc7280.dtsi b/arch/arm64/boot/dts/qcom/sc7280.dtsi
> index a646405..4afe53b 100644
> --- a/arch/arm64/boot/dts/qcom/sc7280.dtsi
> +++ b/arch/arm64/boot/dts/qcom/sc7280.dtsi
> @@ -3899,11 +3899,6 @@
> remote-endpoint = <&dpu_intf0_out>;
> };
> };
> -
> - port@1 {
> - reg = <1>;
> - dp_out: endpoint { };
> - };

Please leave it here. It is a part of the SoC, so it should be in SoC dtsi.

> };
>
> dp_opp_table: opp-table {

--
With best wishes
Dmitry