[PATCH linux dev-5.15] ARM: dts: aspeed: ast2600-evb: Enable RX delay on MAC0/MAC1

[Joel Stanley]

On Fri, 18 Mar 2022 at 03:13, Troy Lee <troy_lee at aspeedtech.com> wrote:
>
> Hi Joel,
> > -----Original Message-----
> > From: Joel Stanley <joel at jms.id.au>
> > Sent: Friday, March 18, 2022 10:22 AM
> > To: Howard Chiu <howard_chiu at aspeedtech.com>; Jeremy Kerr
> > <jk at ozlabs.org>
> > Cc: openbmc at lists.ozlabs.org; Troy Lee <troy_lee at aspeedtech.com>
> > Subject: Re: [PATCH linux dev-5.15] ARM: dts: aspeed: ast2600-evb: Enable
> > RX delay on MAC0/MAC1
> >
> > On Thu, 17 Mar 2022 at 06:30, Howard Chiu
> > <howard_chiu at aspeedtech.com> wrote:
> > >
> > > The property 'phy-mode' on ast2600 mac0 and mac1 is recommended to
> > set to 'rgmii-rxid'
> > > which enables the RX interface delay from the PHY chip.
> > > Refer page 45 of SDK User Guide v08.00
> > >
> > > Signed-off-by: Howard Chiu <howard_chiu at aspeedtech.com>
> >
> > Thanks Howard. This makes MAC0 on my AST2600A3 evb work again!
> >
> > mac1 was working fine without the patch. Do you know why?
> > Why do we do this for mac0 and mac1, but not mac2 and mac3?
> Mac0/1 and mac2/3 are physically located on different die, so they have different properties by nature.
> Mac0/1 has smaller delay step.

Make sense. This information should go in the commit message.

> > Because the user guide is not public, can you please quote the relevant
> > information in the commit message.
> The SDK User Guide can be download from Aspeed github.
> https://github.com/AspeedTech-BMC/openbmc/releases/download/v08.00/SDK_User_Guide_v08.00.pdf

Be sure to include this link in the commit mesasge.

>
> Thanks for testing, do you think this patch should send upstream mainline as well?

Yes, please do that.

>
> Troy Lee
>
> > Tested-by: Joel Stanley <joel at jms.id.au>
> >
> > > ---
> > >  arch/arm/boot/dts/aspeed-ast2600-evb.dts | 4 ++--
> > >  1 file changed, 2 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/arch/arm/boot/dts/aspeed-ast2600-evb.dts
> > > b/arch/arm/boot/dts/aspeed-ast2600-evb.dts
> > > index a6382082d38c..9a1979541d2d 100644
> > > --- a/arch/arm/boot/dts/aspeed-ast2600-evb.dts
> > > +++ b/arch/arm/boot/dts/aspeed-ast2600-evb.dts
> > > @@ -116,7 +116,7 @@ ethphy3: ethernet-phy at 0 {
> > >  &mac0 {
> > >         status = "okay";
> > >
> > > -       phy-mode = "rgmii";
> > > +       phy-mode = "rgmii-rxid";
> > >         phy-handle = <&ethphy0>;
> > >
> > >         pinctrl-names = "default";
> > > @@ -127,7 +127,7 @@ &mac0 {
> > >  &mac1 {
> > >         status = "okay";
> > >
> > > -       phy-mode = "rgmii";
> > > +       phy-mode = "rgmii-rxid";
> > >         phy-handle = <&ethphy1>;
> > >
> > >         pinctrl-names = "default";
> > > --
> > > 2.25.1
> > >