[PATCH v2 2/2] arm64: dts: renesas: ulcb: Remove renesas,no-ether-link property

[Simon Horman]

On Thu, Dec 21, 2017 at 05:18:59PM +0200, Vladimir Zapolskiy wrote:
> From: Bogdan Mirea <Bogdan-Stefan_Mirea at mentor.com>
> 
> The present change is a bug fix for AVB link iteratively up/down.
> 
> Steps to reproduce:
> - start AVB TX stream (Using aplay via MSE),
> - disconnect+reconnect the eth cable,
> - after a reconnection the eth connection goes iteratively up/down
>   without user interaction,
> - this may heal after some seconds or even stay for minutes.
> 
> As the documentation specifies, the "renesas,no-ether-link" option
> should be used when a board does not provide a proper AVB_LINK signal.
> There is no need for this option enabled on RCAR H3/M3 Salvator-X/XS
> and ULCB starter kits since the AVB_LINK is correctly handled by HW.
> 
> Choosing to keep or remove the "renesas,no-ether-link" option will
> have impact on the code flow in the following ways:
> - keeping this option enabled may lead to unexpected behavior since
>   the RX & TX are enabled/disabled directly from adjust_link function
>   without any HW interrogation,
> - removing this option, the RX & TX will only be enabled/disabled after
>   HW interrogation. The HW check is made through the LMON pin in PSR
>   register which specifies AVB_LINK signal value (0 - at low level;
>   1 - at high level).
> 
> In conclusion, the present change is also a safety improvement because
> it removes the "renesas,no-ether-link" option leading to a proper way
> of detecting the link state based on HW interrogation and not on
> software heuristic.
> 
> Fixes: 253ed045a34d ("arm64: dts: renesas: Extract common ULCB board support")

The above shuffles the code around but does not introduce the problem
as far as I can see. Instead I think we should use:

Fixes: 144bf6ccb13f ("arm64: dts: h3ulcb: enable EthernetAVB")
Fixes: 883fae315a6a ("arm64: dts: m3ulcb: enable EthernetAVB")

> Signed-off-by: Bogdan Mirea <Bogdan-Stefan_Mirea at mentor.com>
> Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy at mentor.com>
> ---
>  arch/arm64/boot/dts/renesas/ulcb.dtsi | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/arch/arm64/boot/dts/renesas/ulcb.dtsi b/arch/arm64/boot/dts/renesas/ulcb.dtsi
> index be91016e0b48..3e7a6b94e9f8 100644
> --- a/arch/arm64/boot/dts/renesas/ulcb.dtsi
> +++ b/arch/arm64/boot/dts/renesas/ulcb.dtsi
> @@ -145,7 +145,6 @@
>  &avb {
>  	pinctrl-0 = <&avb_pins>;
>  	pinctrl-names = "default";
> -	renesas,no-ether-link;
>  	phy-handle = <&phy0>;
>  	status = "okay";
>  
> -- 
> 2.8.1
>