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From:   Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Date:   Sat, 26 Sep 2020 00:15:59 +0200
Message-ID: <CAFBinCB4woR1sZfT3tvCkHiR2eRgQfXg3jsD+KO0iMzyQRAGDQ@mail.gmail.com>
Subject: Re: RGMII timing calibration (on 12nm Amlogic SoCs) - integration
 into dwmac-meson8b
To:     Vladimir Oltean <olteanv@gmail.com>
Cc:     f.fainelli@gmail.com, netdev@vger.kernel.org,
        linux-amlogic@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux@armlinux.org.uk,
        peppe.cavallaro@st.com, alexandre.torgue@st.com,
        joabreu@synopsys.com, davem@davemloft.net, kuba@kernel.org
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Hi Vladimir,

On Sat, Sep 26, 2020 at 12:03 AM Vladimir Oltean <olteanv@gmail.com> wrote:
[...]
> > Any recommendations/suggestions/ideas/hints are welcome!
> > Thank you and best regards,
> > Martin
> >
> >
> > [0] https://github.com/khadas/u-boot/blob/4752efbb90b7d048a81760c67f8c826f14baf41c/drivers/net/designware.c#L707
> > [1] https://github.com/khadas/linux/blob/khadas-vims-4.9.y/drivers/net/ethernet/stmicro/stmmac/dwmac-meson.c#L466
>
> Florian attempted something like this before, for the PHY side of things:
> https://patchwork.ozlabs.org/project/netdev/patch/20191015224953.24199-3-f.fainelli@gmail.com/
thank you for this hint!

> There are quite some assumptions to be made if the code is to be made
> generic, such as the fact that the controller should not drop frames
> with bad FCS in hardware. Or if it does, the code should be aware of
> that and check that counter.
I do not need the auto-detection of the phy-mode nor any RX/TX delay
(these are fixed values)
however, from that patch-set I would need most of
phy_rgmii_probe_interface() (and all of the helpers it's using)
also I'm wondering if the "protocol" 0x0808 is recommended over ETH_P_EDSA


Best regards,
Martin