Re: [PATCH v5 3/4] arm64: dts: qcom: sa8775p: remove aux clock from pcie phy

[Ziyue Zhang]

On 7/18/2025 6:53 PM, Konrad Dybcio wrote:
> On 7/18/25 12:02 PM, Johan Hovold wrote:
> > On Fri, Jul 18, 2025 at 04:17:17PM +0800, Ziyue Zhang wrote:
> > > gcc_aux_clk is used in PCIe RC and it is not required in pcie phy, in
> > > pcie phy it should be gcc_phy_aux_clk, so remove gcc_aux_clk and
> > > replace it with gcc_phy_aux_clk.
> > Expanding on why this is a correct change would be good since this does
> > not yet seem to have been fully resolved:
> >
> > 	https://lore.kernel.org/lkml/98088092-1987-41cc-ab70-c9a5d3fdbb41@xxxxxxxxxxxxxxxx/
> I dug out some deep memories and recalled that _PHY_AUX_CLK was
> necessary on x1e for the Gen4 PHY to initialize properly. This
> can be easily reproduced:
>
> diff --git a/arch/arm64/boot/dts/qcom/x1e80100.dtsi b/arch/arm64/boot/dts/qcom/x1e80100.dtsi
> index a9a7bb676c6f..d5ef6bef2b23 100644
> --- a/arch/arm64/boot/dts/qcom/x1e80100.dtsi
> +++ b/arch/arm64/boot/dts/qcom/x1e80100.dtsi
> @@ -3312,7 +3312,7 @@ pcie3_phy: phy@1be0000 {
>                          compatible = "qcom,x1e80100-qmp-gen4x8-pcie-phy";
>                          reg = <0 0x01be0000 0 0x10000>;
>   
> -                       clocks = <&gcc GCC_PCIE_3_PHY_AUX_CLK>,
> +                       clocks = <&gcc GCC_PCIE_3_AUX_CLK>,
>                                   <&gcc GCC_PCIE_3_CFG_AHB_CLK>,
>                                   <&tcsr TCSR_PCIE_8L_CLKREF_EN>,
>                                   <&gcc GCC_PCIE_3_PHY_RCHNG_CLK>,
>
> ==>
> [    6.967231] qcom-qmp-pcie-phy 1be0000.phy: phy initialization timed-out
> [    6.974462] phy phy-1be0000.phy.0: phy poweron failed --> -110
>
> And the (non-PHY_)AUX_CLK is necessary for at least one of them, as
> removing it causes a crash on boot
>
> Konrad