Re: [PATCH 3/4] ARM: dts: ls1021a: Remove num-lanes property from PCIe nodes

From: Andrew Murray
Date: Mon Aug 12 2019 - 04:35:32 EST


On Mon, Aug 12, 2019 at 04:22:27AM +0000, Z.q. Hou wrote:
> From: Hou Zhiqiang <Zhiqiang.Hou@xxxxxxx>
>
> On FSL Layerscape SoCs, the number of lanes assigned to PCIe
> controller is not fixed, it is determined by the selected
> SerDes protocol in the RCW (Reset Configuration Word), and
> the PCIe link training is completed automatically base on
> the selected SerDes protocol, and the link width set-up is
> updated by hardware. So the num-lanes is not needed to
> specify the link width.
>
> The current num-lanes indicates the max lanes PCIe controller
> can support up to, instead of the lanes assigned to the PCIe
> controller. This can result in PCIe link training fail after
> hot-reset. So remove the num-lanes to avoid set-up to incorrect
> link width.
>
> Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@xxxxxxx>
> ---
> arch/arm/boot/dts/ls1021a.dtsi | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/arch/arm/boot/dts/ls1021a.dtsi b/arch/arm/boot/dts/ls1021a.dtsi
> index 464df4290ffc..2f6977ada447 100644
> --- a/arch/arm/boot/dts/ls1021a.dtsi
> +++ b/arch/arm/boot/dts/ls1021a.dtsi
> @@ -874,7 +874,6 @@
> #address-cells = <3>;
> #size-cells = <2>;
> device_type = "pci";
> - num-lanes = <4>;
> num-viewport = <6>;
> bus-range = <0x0 0xff>;
> ranges = <0x81000000 0x0 0x00000000 0x40 0x00010000 0x0 0x00010000 /* downstream I/O */
> @@ -899,7 +898,6 @@
> #address-cells = <3>;
> #size-cells = <2>;
> device_type = "pci";
> - num-lanes = <4>;
> num-viewport = <6>;
> bus-range = <0x0 0xff>;
> ranges = <0x81000000 0x0 0x00000000 0x48 0x00010000 0x0 0x00010000 /* downstream I/O */

Reviewed-by: Andrew Murray <andrew.murray@xxxxxxx>

> --
> 2.17.1
>