[PATCH] ARM: dts: stm32: Disable LAN8710 EDPD on DHCOM

[Alexandre TORGUE]

Hi Marek

On 7/21/21 8:12 PM, Marek Vasut wrote:
> The LAN8710 Energy Detect Power Down (EDPD) functionality might cause
> unreliable cable detection. There are multiple accounts of this in the
> SMSC PHY driver patches which attempted to make EDPD reliable, however
> it seems there is always some sort of corner case left. Unfortunatelly,
> there is no errata documented which would confirm this to be a silicon
> bug on the LAN87xx series of PHYs (LAN8700, LAN8710, LAN8720 at least).
> 
> Disable EDPD on the DHCOM SoM, just like multiple other boards already
> do as well, to make the cable detection reliable.
> 
> Fixes: 34e0c7847dcf ("ARM: dts: stm32: Add DH Electronics DHCOM STM32MP1 SoM and PDK2 board")
> Signed-off-by: Marek Vasut <marex at denx.de>
> Cc: Alexandre Torgue <alexandre.torgue at foss.st.com>
> Cc: Patrice Chotard <patrice.chotard at foss.st.com>
> Cc: Patrick Delaunay <patrick.delaunay at foss.st.com>
> Cc: linux-stm32 at st-md-mailman.stormreply.com
> To: linux-arm-kernel at lists.infradead.org
> ---
>   arch/arm/boot/dts/stm32mp15xx-dhcom-som.dtsi | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/arch/arm/boot/dts/stm32mp15xx-dhcom-som.dtsi b/arch/arm/boot/dts/stm32mp15xx-dhcom-som.dtsi
> index 8349c9099e301..8c41f819f7769 100644
> --- a/arch/arm/boot/dts/stm32mp15xx-dhcom-som.dtsi
> +++ b/arch/arm/boot/dts/stm32mp15xx-dhcom-som.dtsi
> @@ -140,6 +140,7 @@ phy0: ethernet-phy at 1 {
>   			reset-gpios = <&gpioh 3 GPIO_ACTIVE_LOW>;
>   			reset-assert-us = <500>;
>   			reset-deassert-us = <500>;
> +			smsc,disable-energy-detect;
>   			interrupt-parent = <&gpioi>;
>   			interrupts = <11 IRQ_TYPE_LEVEL_LOW>;
>   		};
>

Applied on stm32-next. Note it'll be send through a fixes branch for v5.14.

Regards
alex