Re: [PATCH 5/8] arm64: dts: meson: remove reset-gpios from ethernet node for VIM2 meson-gxm-khadas-vim2

From: Martin Blumenstingl
Date: Fri Sep 25 2020 - 04:04:38 EST


Hello Artem,

(adding back the mailing-list recipients)

On Fri, Sep 25, 2020 at 9:50 AM Art Nikpal <email2tema@xxxxxxxxx> wrote:
>
> hello
>
> > what is the problem that you observe here?
> > did you investigate further why resetting the PHY changes this?
>
> just try next commands
> ifconfig eth0 down && ifconfig eth0 up
> and ethernet never up again - need full reboot only
this means that "something" is either set up incorrectly in the Linux
kernel or that u-boot does some magic (and the same magic is then
missing in the Linux kernel)
I'll dig out my Khadas VIM2 to test this. what should I look out for
(are there any error messages, dhcp not getting an IP address anymore,
etc.)?

> but if reset-gpios will be remove it works fine already - i have checked it many times
>
> for example VIM3 same didnt use reset-gpios
that's interesting - I'm surprised to see this
I did a quick check and for 15 out of 18 .dts(i) files with RGMII
phy-mode we use the reset-gpios:
$ grep -R 'phy-mode = "rgmii' arch/arm64/boot/dts/amlogic/ | wc -l
18
$ grep -R 'ethernet-phy@0' -A10 arch/arm64/boot/dts/amlogic/ | grep
reset-gpios | wc -l
15

so really I would like to add the reset-gpios to the VIM3 .dtsi as
well once we figured out what's wrong on the VIM2


Best regards,
Martin