[PATCH] arm64: dts: clearfog-gt-8k: set gigabit PHY reset deassert delay

[PATCH] arm64: dts: clearfog-gt-8k: set gigabit PHY reset deassert delay

[Russell King]

If the mv88e6xxx DSA driver is built as a module, it causes the
ethernet driver to re-probe when it's loaded. This in turn causes
the gigabit PHY to be momentarily reset and reprogrammed. However,
we attempt to reprogram the PHY immediately after deasserting reset,
and the PHY ignores the writes.

This results in the PHY operating in the wrong mode, and the copper
link states down.

Set a reset deassert delay of 10ms for the gigabit PHY to avoid this.

Fixes: babc5544c293 ("arm64: dts: clearfog-gt-8k: 1G eth PHY reset signal")
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
 arch/arm64/boot/dts/marvell/armada-8040-clearfog-gt-8k.dts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/boot/dts/marvell/armada-8040-clearfog-gt-8k.dts b/arch/arm64/boot/dts/marvell/armada-8040-clearfog-gt-8k.dts
index bd881497b872..dc531d136273 100644
--- a/arch/arm64/boot/dts/marvell/armada-8040-clearfog-gt-8k.dts
+++ b/arch/arm64/boot/dts/marvell/armada-8040-clearfog-gt-8k.dts
@@ -367,6 +367,7 @@
 		pinctrl-0 = <&cp0_copper_eth_phy_reset>;
 		reset-gpios = <&cp0_gpio2 11 GPIO_ACTIVE_LOW>;
 		reset-assert-us = <10000>;
+		reset-deassert-us = <10000>;
 	};
 
 	switch0: switch0@4 {
-- 
2.20.1

Re: [PATCH] arm64: dts: clearfog-gt-8k: set gigabit PHY reset deassert delay

[Baruch Siach]

Hi Russell,

On Tue, Feb 25, 2020 at 11:45:12AM +0000, Russell King wrote:
> If the mv88e6xxx DSA driver is built as a module, it causes the
> ethernet driver to re-probe when it's loaded. This in turn causes
> the gigabit PHY to be momentarily reset and reprogrammed. However,
> we attempt to reprogram the PHY immediately after deasserting reset,
> and the PHY ignores the writes.
> 
> This results in the PHY operating in the wrong mode, and the copper
> link states down.
> 
> Set a reset deassert delay of 10ms for the gigabit PHY to avoid this.
> 
> Fixes: babc5544c293 ("arm64: dts: clearfog-gt-8k: 1G eth PHY reset signal")
> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

Acked-by: Baruch Siach <baruch@tkos.co.il>

Thanks,
baruch

> ---
>  arch/arm64/boot/dts/marvell/armada-8040-clearfog-gt-8k.dts | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/arch/arm64/boot/dts/marvell/armada-8040-clearfog-gt-8k.dts b/arch/arm64/boot/dts/marvell/armada-8040-clearfog-gt-8k.dts
> index bd881497b872..dc531d136273 100644
> --- a/arch/arm64/boot/dts/marvell/armada-8040-clearfog-gt-8k.dts
> +++ b/arch/arm64/boot/dts/marvell/armada-8040-clearfog-gt-8k.dts
> @@ -367,6 +367,7 @@
>  		pinctrl-0 = <&cp0_copper_eth_phy_reset>;
>  		reset-gpios = <&cp0_gpio2 11 GPIO_ACTIVE_LOW>;
>  		reset-assert-us = <10000>;
> +		reset-deassert-us = <10000>;
>  	};
>  
>  	switch0: switch0@4 {

-- 
     http://baruch.siach.name/blog/                  ~. .~   Tk Open Systems
=}------------------------------------------------ooO--U--Ooo------------{=
   - baruch@tkos.co.il - tel: +972.2.679.5364, http://www.tkos.co.il -

Re: [PATCH] arm64: dts: clearfog-gt-8k: set gigabit PHY reset deassert delay

[Gregory CLEMENT]

Hi Russell,

> If the mv88e6xxx DSA driver is built as a module, it causes the
> ethernet driver to re-probe when it's loaded. This in turn causes
> the gigabit PHY to be momentarily reset and reprogrammed. However,
> we attempt to reprogram the PHY immediately after deasserting reset,
> and the PHY ignores the writes.
>
> This results in the PHY operating in the wrong mode, and the copper
> link states down.
>
> Set a reset deassert delay of 10ms for the gigabit PHY to avoid this.
>
> Fixes: babc5544c293 ("arm64: dts: clearfog-gt-8k: 1G eth PHY reset signal")
> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>


Applied on mvebu/dt64

Thanks,

Gregory

> ---
>  arch/arm64/boot/dts/marvell/armada-8040-clearfog-gt-8k.dts | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/arch/arm64/boot/dts/marvell/armada-8040-clearfog-gt-8k.dts b/arch/arm64/boot/dts/marvell/armada-8040-clearfog-gt-8k.dts
> index bd881497b872..dc531d136273 100644
> --- a/arch/arm64/boot/dts/marvell/armada-8040-clearfog-gt-8k.dts
> +++ b/arch/arm64/boot/dts/marvell/armada-8040-clearfog-gt-8k.dts
> @@ -367,6 +367,7 @@
>  		pinctrl-0 = <&cp0_copper_eth_phy_reset>;
>  		reset-gpios = <&cp0_gpio2 11 GPIO_ACTIVE_LOW>;
>  		reset-assert-us = <10000>;
> +		reset-deassert-us = <10000>;
>  	};
>  
>  	switch0: switch0@4 {
> -- 
> 2.20.1
>

-- 
Gregory Clement, Bootlin
Embedded Linux and Kernel engineering
http://bootlin.com