[PATCH] ARC: [plat-hsdk]: Switch ethernet phy-mode to rgmii-id

[Alexey Brodkin]

Hi Vineet, Evgeniy!

> From: Vineet Gupta <vgupta at synopsys.com>
> Sent: Tuesday, September 1, 2020 9:41 PM
> To: Evgeniy Didin <didin at synopsys.com>; linux-snps-arc at lists.infradead.org <linux-snps-arc at lists.infradead.org>
> Cc: Alexey Brodkin <abrodkin at synopsys.com>; Eugeniy Paltsev <paltsev at synopsys.com>
> Subject: Re: [PATCH] ARC: [plat-hsdk]: Switch ethernet phy-mode to rgmii-id 
>  
> On 7/7/20 8:38 AM, Evgeniy Didin wrote:
> > HSDK board has Micrel KSZ9031, recent commit
> > bcf3440c6dd ("net: phy: micrel: add phy-mode support for the KSZ9031 PHY")
> > caused a breakdown of Ethernet.
> > Using 'phy-mode = "rgmii"' is not correct because accodring RGMII
> > specification it is necessary to have delay on RX (PHY to MAX)
> > which is not generated in case of "rgmii".
> > Using "rgmii-id" adds necessary delay and solves the issue.
> >
> > Also adding name of PHY placed on HSDK board.
> >
> > Signed-off-by: Evgeniy Didin <Evgeniy.Didin at synopsys.com>
> > Cc: Eugeniy Paltsev <Eugeniy.Paltsev at synopsys.com>
> > Cc: Alexey Brodkin <abrodkin at synopsys.com>
> 
> @Alexey - u ok with this change ?

Sure,

Acked-by: Alexey Brodkin <abrodkin at synopsys.com>

> 
> -Vineet
> 
> > ---
> >  arch/arc/boot/dts/hsdk.dts | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/arc/boot/dts/hsdk.dts b/arch/arc/boot/dts/hsdk.dts
> > index 9acbeba832c0..d6427d47e5a1 100644
> > --- a/arch/arc/boot/dts/hsdk.dts
> > +++ b/arch/arc/boot/dts/hsdk.dts
> > @@ -208,7 +208,7 @@
> >                        reg = <0x8000 0x2000>;
> >                        interrupts = <10>;
> >                        interrupt-names = "macirq";
> > -                     phy-mode = "rgmii";
> > +                     phy-mode = "rgmii-id";
> >                        snps,pbl = <32>;
> >                        snps,multicast-filter-bins = <256>;
> >                        clocks = <&gmacclk>;
> > @@ -226,7 +226,7 @@
> >                                #address-cells = <1>;
> >                                #size-cells = <0>;
> >                                compatible = "snps,dwmac-mdio";
> > -                             phy0: ethernet-phy at 0 {
> > +                             phy0: ethernet-phy at 0 { /* Micrel KSZ9031 */
> >                                        reg = <0>;
> >                                };
> >                        };
>