Re: [PATCH next] ARM: dts: am437x: fix networking on boards with ksz9031 phy

From: Grygorii Strashko
Date: Thu May 07 2020 - 11:13:48 EST




On 07/05/2020 07:40, Oleksij Rempel wrote:
Hi Grygorii,

thank you for you patches!

On Wed, May 06, 2020 at 10:08:35PM +0300, Grygorii Strashko wrote:
Since commit bcf3440c6dd7 ("net: phy: micrel: add phy-mode support for the
KSZ9031 PHY") the networking is broken on boards:
am437x-gp-evm
am437x-sk-evm
am437x-idk-evm

All above boards have phy-mode = "rgmii" and this is worked before, because
KSZ9031 PHY started with default RGMII internal delays configuration (TX
off, RX on 1.2 ns) and MAC provided TX delay. After above commit, the
KSZ9031 PHY starts handling phy mode properly and disables RX delay, as
result networking is become broken.

Fix it by switching to phy-mode = "rgmii-rxid" to reflect previous
behavior.

Cc: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
Cc: Andrew Lunn <andrew@xxxxxxx>
Cc: Philippe Schenker <philippe.schenker@xxxxxxxxxxx>
Fixes: commit bcf3440c6dd7 ("net: phy: micrel: add phy-mode support for the KSZ9031 PHY")
Signed-off-by: Grygorii Strashko <grygorii.strashko@xxxxxx>
---
arch/arm/boot/dts/am437x-gp-evm.dts | 2 +-
arch/arm/boot/dts/am437x-idk-evm.dts | 2 +-
arch/arm/boot/dts/am437x-sk-evm.dts | 4 ++--
3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/arm/boot/dts/am437x-gp-evm.dts b/arch/arm/boot/dts/am437x-gp-evm.dts
index 811c8cae315b..d692e3b2812a 100644
--- a/arch/arm/boot/dts/am437x-gp-evm.dts
+++ b/arch/arm/boot/dts/am437x-gp-evm.dts
@@ -943,7 +943,7 @@
&cpsw_emac0 {
phy-handle = <&ethphy0>;
- phy-mode = "rgmii";
+ phy-mode = "rgmii-rxid";
};
&elm {
diff --git a/arch/arm/boot/dts/am437x-idk-evm.dts b/arch/arm/boot/dts/am437x-idk-evm.dts
index 9f66f96d09c9..a7495fb364bf 100644
--- a/arch/arm/boot/dts/am437x-idk-evm.dts
+++ b/arch/arm/boot/dts/am437x-idk-evm.dts
@@ -504,7 +504,7 @@
&cpsw_emac0 {
phy-handle = <&ethphy0>;
- phy-mode = "rgmii";
+ phy-mode = "rgmii-id";
};

Do you have here really rgmii-id?


Right, thanks you.

--
Best regards,
grygorii