Re: [PATCH v2] arm64: dts: qcom: x1e80100: Switch PCIe 6a to 4 lanes mode

[Dmitry Baryshkov]

On Fri, Oct 04, 2024 at 12:06:33PM GMT, Abel Vesa wrote:
> The PCIe 6a controller and PHY can be configured in 4-lanes mode or
> 2-lanes mode. For 4-lanes mode, it fetches the lanes provided by PCIe 6b.
> For 2-lanes mode, PCIe 6a uses 2 lanes and then PCIe 6b uses the other 2
> lanes. Configure it in 4-lane mode and then each board can configure it
> depending on the design. Both the QCP and CRD boards, currently upstream,
> use PCIe 6a for NVMe in 4-lane mode. Mark the controller as 4-lane as
> well. This is the last change needed in order to support NVMe with Gen4
> 4-lanes on all existing X Elite boards.

What about other X1E80100 devices supported upstream? Do they also use
this controller in 4 lane mode?

> 
> Signed-off-by: Abel Vesa <abel.vesa@xxxxxxxxxx>
> ---
> Changes in v2:
> - Re-worded the commit message according to Johan's suggestions
> - Dropped the clocks changes.
> - Dropped the fixes tag as this relies on the Gen4 4-lanes stability
>   patchset which has been only merged in 6.12, so backporting this patch
>   would break NVMe support for all platforms.
> - Link to v1: https://lore.kernel.org/r/20240531-x1e80100-dts-fixes-pcie6a-v1-2-1573ebcae1e8@xxxxxxxxxx
> ---
>  arch/arm64/boot/dts/qcom/x1e80100.dtsi | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/arm64/boot/dts/qcom/x1e80100.dtsi b/arch/arm64/boot/dts/qcom/x1e80100.dtsi
> index a36076e3c56b5b8815eb41ec55e2e1e5bd878201..4ec712cb7a26d8fe434631cf15949524fd22c7d9 100644
> --- a/arch/arm64/boot/dts/qcom/x1e80100.dtsi
> +++ b/arch/arm64/boot/dts/qcom/x1e80100.dtsi
> @@ -2931,7 +2931,7 @@ pcie6a: pci@1bf8000 {
>  			dma-coherent;
>  
>  			linux,pci-domain = <6>;
> -			num-lanes = <2>;
> +			num-lanes = <4>;
>  
>  			interrupts = <GIC_SPI 773 IRQ_TYPE_LEVEL_HIGH>,
>  				     <GIC_SPI 774 IRQ_TYPE_LEVEL_HIGH>,
> @@ -2997,8 +2997,9 @@ &mc_virt SLAVE_EBI1 QCOM_ICC_TAG_ALWAYS>,
>  		};
>  
>  		pcie6a_phy: phy@1bfc000 {
> -			compatible = "qcom,x1e80100-qmp-gen4x2-pcie-phy";
> -			reg = <0 0x01bfc000 0 0x2000>;
> +			compatible = "qcom,x1e80100-qmp-gen4x4-pcie-phy";

Oh...

> +			reg = <0 0x01bfc000 0 0x2000>,
> +			      <0 0x01bfe000 0 0x2000>;
>  
>  			clocks = <&gcc GCC_PCIE_6A_PHY_AUX_CLK>,
>  				 <&gcc GCC_PCIE_6A_CFG_AHB_CLK>,
> @@ -3021,6 +3022,8 @@ pcie6a_phy: phy@1bfc000 {
>  
>  			power-domains = <&gcc GCC_PCIE_6_PHY_GDSC>;
>  
> +			qcom,4ln-config-sel = <&tcsr 0x1a000 0>;
> +
>  			#clock-cells = <0>;
>  			clock-output-names = "pcie6a_pipe_clk";
>  
> 
> ---
> base-commit: c02d24a5af66a9806922391493205a344749f2c4
> change-id: 20241003-x1e80100-dts-fixes-pcie6a-b9f1171e8d5b
> 
> Best regards,
> -- 
> Abel Vesa <abel.vesa@xxxxxxxxxx>
> 

-- 
With best wishes
Dmitry