Message-ID: <a824a7f6-0a62-7cab-180b-f20297311a2b@collabora.com>
Date:   Fri, 17 Feb 2023 02:32:45 +0200
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Subject: Re: [PATCH 07/12] dt-bindings: net: Add StarFive JH7100 SoC
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To:     Andrew Lunn <andrew@lunn.ch>
Cc:     Lee Jones <lee@kernel.org>, Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Emil Renner Berthing <kernel@esmil.dk>,
        Conor Dooley <conor@kernel.org>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Giuseppe Cavallaro <peppe.cavallaro@st.com>,
        Alexandre Torgue <alexandre.torgue@foss.st.com>,
        Jose Abreu <joabreu@synopsys.com>,
        Maxime Coquelin <mcoquelin.stm32@gmail.com>,
        Richard Cochran <richardcochran@gmail.com>,
        Sagar Kadam <sagar.kadam@sifive.com>,
        Yanhong Wang <yanhong.wang@starfivetech.com>,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        netdev@vger.kernel.org, linux-riscv@lists.infradead.org,
        linux-stm32@st-md-mailman.stormreply.com,
        linux-arm-kernel@lists.infradead.org, kernel@collabora.com
References: <20230211031821.976408-1-cristian.ciocaltea@collabora.com>
 <20230211031821.976408-8-cristian.ciocaltea@collabora.com>
 <Y+e74UIV/Td91lKB@lunn.ch>
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From:   Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
In-Reply-To: <Y+5t4Jlb0ytw40pu@lunn.ch>
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On 2/16/23 19:54, Andrew Lunn wrote:
>> I gave "rgmii-id" a try and it's not usable, I get too many errors. So
>> "rgmii" should be the right choice here.
> 
> I would actually say it shows we don't understand what is going on
> with delays. "rgmii" is not every often the correct value. The fact it
> works suggests the MAC is adding delays.
> 
> What value are you using for starfive,gtxclk-dlychain ? 

This is set to '4' in patch 12/12.

> Try 0 and then "rgmii-id"

I made some more tests and it seems the only stable configuration is 
"rgmii" with "starfive,gtxclk-dlychain" set to 4:

phy-mode | dlychain | status
---------+----------+--------------------------------------------
rgmii    |        4 | OK (no issues observed)
rgmii-id |        4 | BROKEN (errors reported [1])
rgmii    |        0 | UNRELIABLE (no errors, but frequent stalls)
rgmii-id |        0 | BROKEN (errors reported)

[1] Reported errors in case of BROKEN status:
$ grep '' /sys/class/net/eth0/statistics/* | grep -v ':0$'

/sys/class/net/eth0/statistics/rx_crc_errors:6
/sys/class/net/eth0/statistics/rx_errors:6
/sys/class/net/eth0/statistics/tx_bytes:10836
/sys/class/net/eth0/statistics/tx_packets:46

> 	Andrew			
>