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References: <20210212025806.556217-1-nobuhiro1.iwamatsu@toshiba.co.jp> <20210212025806.556217-5-nobuhiro1.iwamatsu@toshiba.co.jp>
In-Reply-To: <20210212025806.556217-5-nobuhiro1.iwamatsu@toshiba.co.jp>
From:   Arnd Bergmann <arnd@kernel.org>
Date:   Fri, 12 Feb 2021 10:32:09 +0100
Message-ID: <CAK8P3a0Wycgn=Dq8KE+-F2keWj4mKaYQ=Y5RLefYn4gc71vVFw@mail.gmail.com>
Subject: Re: [PATCH v2 4/4] arm: dts: visconti: Add DT support for Toshiba
 Visconti5 ethernet controller
To:     Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
Cc:     "David S . Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Giuseppe Cavallaro <peppe.cavallaro@st.com>,
        Alexandre Torgue <alexandre.torgue@st.com>,
        Jose Abreu <joabreu@synopsys.com>,
        DTML <devicetree@vger.kernel.org>,
        Networking <netdev@vger.kernel.org>,
        punit1.agrawal@toshiba.co.jp, yuji2.ishikawa@toshiba.co.jp,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
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On Fri, Feb 12, 2021 at 4:03 AM Nobuhiro Iwamatsu
<nobuhiro1.iwamatsu@toshiba.co.jp> wrote:
> @@ -384,6 +398,16 @@ spi6: spi@28146000 {
>                         #size-cells = <0>;
>                         status = "disabled";
>                 };
> +
> +               piether: ethernet@28000000 {
> +                       compatible = "toshiba,visconti-dwmac";

Shouldn't there be a more specific compatible string here, as well as the
particular version of the dwmac you use?

In the binding example, you list the device as "dma-coherent",
but in this instance, it is not marked that way. Can you find out
whether the device is in fact connected properly to a cache-coherent
bus?

Note that failing to mark it as cache-coherent will make the device
rather slow and possibly not work correctly if it is in fact coherent,
but the default is non-coherent since a lot of SoCs are lacking
that hardware support.

       Arnd