RE: [PATCH 1/2] arm64: dts: renesas: hihope-rzg2-ex: Drop rxc-skew-ps from ethernet-phy node

From: Biju Das <biju.das.jz@bp.renesas.com>
To: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Rob Herring <robh+dt@kernel.org>,
	Magnus Damm <magnus.damm@gmail.com>,
	Chris Paterson <Chris.Paterson2@renesas.com>,
	Biju Das <biju.das@bp.renesas.com>,
	Simon Horman <horms+renesas@verge.net.au>,
	Linux-Renesas <linux-renesas-soc@vger.kernel.org>,
	"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
	<devicetree@vger.kernel.org>,
	Prabhakar Mahadev Lad <prabhakar.mahadev-lad.rj@bp.renesas.com>
Subject: RE: [PATCH 1/2] arm64: dts: renesas: hihope-rzg2-ex: Drop rxc-skew-ps from ethernet-phy node
Date: Fri, 16 Oct 2020 06:15:22 +0000	[thread overview]
Message-ID: <TYBPR01MB53091FA117DF513BAF6A46E486030@TYBPR01MB5309.jpnprd01.prod.outlook.com> (raw)
In-Reply-To: <CAMuHMdUogbfHYv+g3+2=7JwhgH3MngmDEe5nvjZwkjTOJyn9dQ@mail.gmail.com>

Hi Geert,

Thanks for the feedback.

> Subject: Re: [PATCH 1/2] arm64: dts: renesas: hihope-rzg2-ex: Drop rxc-
> skew-ps from ethernet-phy node
> 
> Hi Biju,
> 
> On Thu, Oct 15, 2020 at 3:24 PM Biju Das <biju.das.jz@bp.renesas.com>
> wrote:
> > HiHope RZG2[HMN] boards uses Realtek phy and the driver does not
> > support rxc-skew-ps property. So remove rxc-skew-ps from ethernet-phy
> node.
> >
> > Fixes: 7433f1fb8ec8fe ("arm64: dts: renesas: Add HiHope RZ/G2M sub
> > board support")
> > Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> > Reviewed-by: Lad Prabhakar <prabhakar.mahadev-
> lad.rj@bp.renesas.com>
> 
> Thanks for your patch!
> 
> > --- a/arch/arm64/boot/dts/renesas/hihope-rzg2-ex.dtsi
> > +++ b/arch/arm64/boot/dts/renesas/hihope-rzg2-ex.dtsi
> > @@ -23,7 +23,6 @@
> >         status = "okay";
> >
> >         phy0: ethernet-phy@0 {
> > -               rxc-skew-ps = <1500>;
> >                 reg = <0>;
> >                 interrupt-parent = <&gpio2>;
> >                 interrupts = <11 IRQ_TYPE_LEVEL_LOW>;
> 
> Should "rx-internal-delay-ps = <1800>" be added to the avb node instead
> (after [1] has entered v5.10-rc1, and the DTS part of [2] has been  applied to
> renesas-devel)?

Looking at the schematic, it is not needed, since it has "2ns" internal delay  (4.7K Ohm latched to 2.5 V) on the Rx side.

Cheers,
Biju

> [1] [PATCH net-next v4 resend 5/5] ravb: Add support for explicit internal
> clock delay configuration
>     https://lore.kernel.org/linux-renesas-soc/20201001101008.14365-6-
> geert+renesas@glider.be/
> [2] [PATCH v3 0/7] net/ravb: Add support for explicit internal clock delay
> configuration
>     https://lore.kernel.org/linux-renesas-soc/20200819134344.27813-1-
> geert+renesas@glider.be
> 
> Gr{oetje,eeting}s,
> 
>                         Geert
> 
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-
> m68k.org
> 
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                 -- Linus Torvalds