Patch "arm64: dts: renesas: ulcb: Remove renesas, no-ether-link property" has been added to the 4.14-stable tree

This is a note to let you know that I've just added the patch titled

arm64: dts: renesas: ulcb: Remove renesas, no-ether-link property

to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
arm64-dts-renesas-ulcb-remove-renesas-no-ether-link-property.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Bogdan Mirea <[email protected]>
Date: Thu, 21 Dec 2017 17:18:59 +0200
Subject: arm64: dts: renesas: ulcb: Remove renesas, no-ether-link property

From: Bogdan Mirea <[email protected]>

[ Upstream commit 7d2901f809c110bd9a261e879d59efe62e3bc758 ]

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.

---
 arch/arm64/boot/dts/renesas/ulcb.dtsi |    1 -
 1 file changed, 1 deletion(-)

@@ -145,7 +145,6 @@
 &avb {
 	pinctrl-0 = <&avb_pins>;
 	pinctrl-names = "default";
-	renesas,no-ether-link;
 	phy-handle = <&phy0>;
 	status = "okay";
 

Patches currently in stable-queue which might be from [email protected] are

queue-4.14/arm64-dts-renesas-ulcb-remove-renesas-no-ether-link-property.patch