2023-09-28 18:48:36

by Manivannan Sadhasivam

Subject: Re: [PATCH v5 2/5] arm64: dts: qcom: sm8450: Add opp table support to PCIe

On Thu, Sep 07, 2023 at 11:30:30AM +0530, Krishna chaitanya chundru wrote:
> PCIe needs to choose the appropriate performance state of RPMH power
> domain based up on the PCIe gen speed.
>
> So let's add the OPP table support to specify RPMH performance states.
>
> Use opp-level for the PCIe gen speed for easier use.
>

So, you just want to control RPMh performance state using OPP and not clock
rates? What will happen if you switch to lowest performance state of RPMh but
still run PCIe clocks at max rate?

- Mani

> Signed-off-by: Krishna chaitanya chundru <[email protected]>
> ---
> arch/arm64/boot/dts/qcom/sm8450.dtsi | 47 ++++++++++++++++++++++++++++++++++++
> 1 file changed, 47 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/qcom/sm8450.dtsi b/arch/arm64/boot/dts/qcom/sm8450.dtsi
> index 2a60cf8..a6264a5 100644
> --- a/arch/arm64/boot/dts/qcom/sm8450.dtsi
> +++ b/arch/arm64/boot/dts/qcom/sm8450.dtsi
> @@ -1820,7 +1820,28 @@
> pinctrl-names = "default";
> pinctrl-0 = <&pcie0_default_state>;
>
> + operating-points-v2 = <&pcie0_opp_table>;
> +
> status = "disabled";
> +
> + pcie0_opp_table: opp-table {
> + compatible = "operating-points-v2";
> +
> + opp-1 {
> + opp-level = <1>;
> + required-opps = <&rpmhpd_opp_low_svs>;
> + };
> +
> + opp-2 {
> + opp-level = <2>;
> + required-opps = <&rpmhpd_opp_low_svs>;
> + };
> +
> + opp-3 {
> + opp-level = <3>;
> + required-opps = <&rpmhpd_opp_nom>;
> + };
> + };
> };
>
> pcie0_phy: phy@1c06000 {
> @@ -1932,7 +1953,33 @@
> pinctrl-names = "default";
> pinctrl-0 = <&pcie1_default_state>;
>
> + operating-points-v2 = <&pcie1_opp_table>;
> +
> status = "disabled";
> +
> + pcie1_opp_table: opp-table {
> + compatible = "operating-points-v2";
> +
> + opp-1 {
> + opp-level = <1>;
> + required-opps = <&rpmhpd_opp_low_svs>;
> + };
> +
> + opp-2 {
> + opp-level = <2>;
> + required-opps = <&rpmhpd_opp_low_svs>;
> + };
> +
> + opp-3 {
> + opp-level = <3>;
> + required-opps = <&rpmhpd_opp_low_svs>;
> + };
> +
> + opp-4 {
> + opp-level = <4>;
> + required-opps = <&rpmhpd_opp_nom>;
> + };
> + };
> };
>
> pcie1_phy: phy@1c0f000 {
> --
> 2.7.4
>

--
மணிவண்ணன் சதாசிவம்

2023-10-05 14:53:33

by Krishna chaitanya chundru

Subject: Re: [PATCH v5 2/5] arm64: dts: qcom: sm8450: Add opp table support to PCIe

On 9/29/2023 12:08 AM, Manivannan Sadhasivam wrote:
> On Thu, Sep 07, 2023 at 11:30:30AM +0530, Krishna chaitanya chundru wrote:
>> PCIe needs to choose the appropriate performance state of RPMH power
>> domain based up on the PCIe gen speed.
>>
>> So let's add the OPP table support to specify RPMH performance states.
>>
>> Use opp-level for the PCIe gen speed for easier use.
>>
> So, you just want to control RPMh performance state using OPP and not clock
> rates? What will happen if you switch to lowest performance state of RPMh but
> still run PCIe clocks at max rate?
>
> - Mani

Based up on the RPMH state the clock rates will be scaled accordingly.

- KC

>> Signed-off-by: Krishna chaitanya chundru <[email protected]>
>> ---
>> arch/arm64/boot/dts/qcom/sm8450.dtsi | 47 ++++++++++++++++++++++++++++++++++++
>> 1 file changed, 47 insertions(+)
>>
>> diff --git a/arch/arm64/boot/dts/qcom/sm8450.dtsi b/arch/arm64/boot/dts/qcom/sm8450.dtsi
>> index 2a60cf8..a6264a5 100644
>> --- a/arch/arm64/boot/dts/qcom/sm8450.dtsi
>> +++ b/arch/arm64/boot/dts/qcom/sm8450.dtsi
>> @@ -1820,7 +1820,28 @@
>> pinctrl-names = "default";
>> pinctrl-0 = <&pcie0_default_state>;
>>
>> + operating-points-v2 = <&pcie0_opp_table>;
>> +
>> status = "disabled";
>> +
>> + pcie0_opp_table: opp-table {
>> + compatible = "operating-points-v2";
>> +
>> + opp-1 {
>> + opp-level = <1>;
>> + required-opps = <&rpmhpd_opp_low_svs>;
>> + };
>> +
>> + opp-2 {
>> + opp-level = <2>;
>> + required-opps = <&rpmhpd_opp_low_svs>;
>> + };
>> +
>> + opp-3 {
>> + opp-level = <3>;
>> + required-opps = <&rpmhpd_opp_nom>;
>> + };
>> + };
>> };
>>
>> pcie0_phy: phy@1c06000 {
>> @@ -1932,7 +1953,33 @@
>> pinctrl-names = "default";
>> pinctrl-0 = <&pcie1_default_state>;
>>
>> + operating-points-v2 = <&pcie1_opp_table>;
>> +
>> status = "disabled";
>> +
>> + pcie1_opp_table: opp-table {
>> + compatible = "operating-points-v2";
>> +
>> + opp-1 {
>> + opp-level = <1>;
>> + required-opps = <&rpmhpd_opp_low_svs>;
>> + };
>> +
>> + opp-2 {
>> + opp-level = <2>;
>> + required-opps = <&rpmhpd_opp_low_svs>;
>> + };
>> +
>> + opp-3 {
>> + opp-level = <3>;
>> + required-opps = <&rpmhpd_opp_low_svs>;
>> + };
>> +
>> + opp-4 {
>> + opp-level = <4>;
>> + required-opps = <&rpmhpd_opp_nom>;
>> + };
>> + };
>> };
>>
>> pcie1_phy: phy@1c0f000 {
>> --
>> 2.7.4
>>