[PATCH 02/10] ARM: dts: sun6i: a31-hummingbird: Enable RGMII RX/TX delay on Ethernet PHY

[Chen-Yu Tsai]

From: Chen-Yu Tsai <we...@csie.org>

The Ethernet PHY on the A31 Hummingbird has the RX and TX delays
enabled on the PHY, using pull-ups on the RXDLY and TXDLY pins.

Fix the phy-mode description to correct reflect this so that the
implementation doesn't reconfigure the delays incorrectly. This
happened with commit bbc4d71d6354 ("net: phy: realtek: fix rtl8211e
rx/tx delay config").

Fixes: c220aec2bb79 ("ARM: dts: sun6i: Add Merrii A31 Hummingbird support")
Signed-off-by: Chen-Yu Tsai <we...@csie.org>
---
arch/arm/boot/dts/sun6i-a31-hummingbird.dts | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/sun6i-a31-hummingbird.dts b/arch/arm/boot/dts/sun6i-a31-hummingbird.dts
index 049e6ab3cf56..73de34ae37fd 100644
--- a/arch/arm/boot/dts/sun6i-a31-hummingbird.dts
+++ b/arch/arm/boot/dts/sun6i-a31-hummingbird.dts
@@ -154,7 +154,7 @@ &gmac {
pinctrl-names = "default";
pinctrl-0 = <&gmac_rgmii_pins>;
phy-handle = <&phy1>;
- phy-mode = "rgmii";
+ phy-mode = "rgmii-id";
status = "okay";
};

--
2.28.0

[Icenowy Zheng]

在 2020-10-25星期日的 00:25 +0800，Chen-Yu Tsai写道：

> From: Chen-Yu Tsai <we...@csie.org>
>
> The Ethernet PHY on the A31 Hummingbird has the RX and TX delays
> enabled on the PHY, using pull-ups on the RXDLY and TXDLY pins.
>
> Fix the phy-mode description to correct reflect this so that the
> implementation doesn't reconfigure the delays incorrectly. This
> happened with commit bbc4d71d6354 ("net: phy: realtek: fix rtl8211e
> rx/tx delay config").

Personally I think they should revert this commit, and consider other
solution.

This commit breaks everything.

(Although the patch on individual DT patches are technically correct)

[Jernej Škrabec]

Dne sobota, 24. oktober 2020 ob 19:51:06 CEST je Icenowy Zheng napisal(a):

> 在 2020-10-25星期日的 00:25 +0800，Chen-Yu Tsai写道：
>
> > From: Chen-Yu Tsai <we...@csie.org>
> >
> > The Ethernet PHY on the A31 Hummingbird has the RX and TX delays
> > enabled on the PHY, using pull-ups on the RXDLY and TXDLY pins.
> >
> > Fix the phy-mode description to correct reflect this so that the
> > implementation doesn't reconfigure the delays incorrectly. This
> > happened with commit bbc4d71d6354 ("net: phy: realtek: fix rtl8211e
> > rx/tx delay config").
>
> Personally I think they should revert this commit, and consider other
> solution.
>
> This commit breaks everything.
>

Previously broken driver allowed inproper DT to work, so you have to fix
everything eventually.

Plus side, there is no need to have hack for Pine64 Plus ethernet anymore.

Best regards,
Jernej

[Icenowy Zheng]

于 2020年10月25日 GMT+08:00 上午2:30:35, "Jernej Škrabec" <jernej....@siol.net> 写到:

>Dne sobota, 24. oktober 2020 ob 19:51:06 CEST je Icenowy Zheng
>napisal(a):
>> 在 2020-10-25星期日的 00:25 +0800，Chen-Yu Tsai写道：
>>
>> > From: Chen-Yu Tsai <we...@csie.org>
>> >
>> > The Ethernet PHY on the A31 Hummingbird has the RX and TX delays
>> > enabled on the PHY, using pull-ups on the RXDLY and TXDLY pins.
>> >
>> > Fix the phy-mode description to correct reflect this so that the
>> > implementation doesn't reconfigure the delays incorrectly. This
>> > happened with commit bbc4d71d6354 ("net: phy: realtek: fix rtl8211e
>> > rx/tx delay config").
>>
>> Personally I think they should revert this commit, and consider other
>> solution.
>>
>> This commit breaks everything.
>>
>
>Previously broken driver allowed inproper DT to work, so you have to
>fix
>everything eventually.

There is no "improper DT" if it's already shipped, DT should suffer driver
change, not changed to match driver.

I think at least Fedora tends to ship a DT with a system image that will
not get updated when kernel gets updated.

[Clément Péron]

Hi,

On Sat, 24 Oct 2020 at 20:39, Icenowy Zheng <ice...@aosc.io> wrote:
>
>
>
> 于 2020年10月25日 GMT+08:00 上午2:30:35, "Jernej Škrabec" <jernej....@siol.net> 写到:
> >Dne sobota, 24. oktober 2020 ob 19:51:06 CEST je Icenowy Zheng
> >napisal(a):
> >> 在 2020-10-25星期日的 00:25 +0800，Chen-Yu Tsai写道：
> >>
> >> > From: Chen-Yu Tsai <we...@csie.org>
> >> >
> >> > The Ethernet PHY on the A31 Hummingbird has the RX and TX delays
> >> > enabled on the PHY, using pull-ups on the RXDLY and TXDLY pins.
> >> >
> >> > Fix the phy-mode description to correct reflect this so that the
> >> > implementation doesn't reconfigure the delays incorrectly. This
> >> > happened with commit bbc4d71d6354 ("net: phy: realtek: fix rtl8211e
> >> > rx/tx delay config").
> >>
> >> Personally I think they should revert this commit, and consider other
> >> solution.
> >>
> >> This commit breaks everything.
> >>
> >
> >Previously broken driver allowed inproper DT to work, so you have to
> >fix
> >everything eventually.
>
> There is no "improper DT" if it's already shipped, DT should suffer driver
> change, not changed to match driver.
>
> I think at least Fedora tends to ship a DT with a system image that will
> not get updated when kernel gets updated.

I think we are missing a phy-mode saying use RGMII but don't change
the delay set by the hardware.
Or maybe introduce a phy-mode='rgmii-noid' to explicitly disable the
RX/TD delay using software bits
and use phy-mode='rgmii' to keep the delay set by the hardware.

Clement

>
> >
> >Plus side, there is no need to have hack for Pine64 Plus ethernet
> >anymore.
> >
> >Best regards,
> >Jernej
> >
> >> (Although the patch on individual DT patches are technically correct)
> >>
> >> > Fixes: c220aec2bb79 ("ARM: dts: sun6i: Add Merrii A31 Hummingbird
> >> > support")
> >> > Signed-off-by: Chen-Yu Tsai <we...@csie.org>
> >> > ---
> >> >
> >> > arch/arm/boot/dts/sun6i-a31-hummingbird.dts | 2 +-
> >> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >> >
> >> > diff --git a/arch/arm/boot/dts/sun6i-a31-hummingbird.dts
> >> > b/arch/arm/boot/dts/sun6i-a31-hummingbird.dts
> >> > index 049e6ab3cf56..73de34ae37fd 100644
> >> > --- a/arch/arm/boot/dts/sun6i-a31-hummingbird.dts
> >> > +++ b/arch/arm/boot/dts/sun6i-a31-hummingbird.dts
> >> > @@ -154,7 +154,7 @@ &gmac {
> >> >
> >> > pinctrl-names = "default";
> >> > pinctrl-0 = <&gmac_rgmii_pins>;
> >> > phy-handle = <&phy1>;
> >> >
> >> > - phy-mode = "rgmii";
> >> > + phy-mode = "rgmii-id";
> >> >
> >> > status = "okay";
> >> >
> >> > };
>

> --
> You received this message because you are subscribed to the Google Groups "linux-sunxi" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to linux-sunxi...@googlegroups.com.
> To view this discussion on the web, visit https://groups.google.com/d/msgid/linux-sunxi/9D317C52-5F28-41A9-80DA-DBADA142B042%40aosc.io.

[Jernej Škrabec]

Dne sobota, 24. oktober 2020 ob 18:25:07 CET je Chen-Yu Tsai napisal(a):

> From: Chen-Yu Tsai <we...@csie.org>
>
> The Ethernet PHY on the A31 Hummingbird has the RX and TX delays
> enabled on the PHY, using pull-ups on the RXDLY and TXDLY pins.
>
> Fix the phy-mode description to correct reflect this so that the
> implementation doesn't reconfigure the delays incorrectly. This
> happened with commit bbc4d71d6354 ("net: phy: realtek: fix rtl8211e
> rx/tx delay config").
>
> Fixes: c220aec2bb79 ("ARM: dts: sun6i: Add Merrii A31 Hummingbird support")
> Signed-off-by: Chen-Yu Tsai <we...@csie.org>

Acked-by: Jernej Skrabec <jernej....@siol.net>

Best regards,
Jernej