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References: <20231117100958.425354-1-robimarko@gmail.com> <20231117100958.425354-2-robimarko@gmail.com>
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From:   Robert Marko <robimarko@gmail.com>
Date:   Tue, 28 Nov 2023 12:57:42 +0100
Message-ID: <CAOX2RU5QWDPguJ1izfipfiGzCO1muFaJQ8=h9PAUD36jdZiUEQ@mail.gmail.com>
Subject: Re: [PATCH net-next 2/2] net: phy: aquantia: enable USXGMII autoneg
 on AQR107
To:     "Russell King (Oracle)" <linux@armlinux.org.uk>
Cc:     andrew@lunn.ch, hkallweit1@gmail.com, davem@davemloft.net,
        edumazet@google.com, kuba@kernel.org, pabeni@redhat.com,
        ansuelsmth@gmail.com, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
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On Fri, 17 Nov 2023 at 13:47, Russell King (Oracle)
<linux@armlinux.org.uk> wrote:
>
> On Fri, Nov 17, 2023 at 11:09:49AM +0100, Robert Marko wrote:
> > In case USXGMII is being used as the PHY interface mode then USXGMII
> > autoneg must be enabled as well.
> >
> > HW defaults to USXGMII autoneg being disabled which then results in
> > autoneg timeout, so enable it in case USXGMII is used.
>
> I was led to believe that the bitfield in bits 8:7 of the
> VEND1_GLOBAL_CFG_* registers, when set to value '1' is something
> to do with selecting USXGMII mode as opposed to 10GBASE-R. Could
> you look in to that and whether that is the more correct way of
> configuring the PHY for USXGMII mode?

Hi,

bits 8:7 in the VEND1_GLOBAL_CFG_* are used to configure the rate
adaptation method.
With the following allowed values:
0 (Default) = No rate adaptation
1 = USX rate adaptation
2 = Pause rate adaptation

I dont think that is related to the issue I am facing here which is
that by default
Bit 3 in the PHY XS Transmit (XAUI Rx) Reserved Vendor Provisioning 2 register
is set to 0.

This means that USX Autoneg Control For MAC is disabled and in USXGMII mode
auto-negotiation between the PHY and MAC will fail/timeout.

I have checked various vendor drivers and they all enable this bit in
case USXGMII
is used.

Regards,
Robert

>
> Thanks.
>
> --
> RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
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