On 12/20/23 15:48, Emil Renner Berthing wrote:
> Cristian Ciocaltea wrote:
>> The StarFive VisionFive V1 SBC uses a Motorcomm YT8521 PHY supporting
>> RGMII-ID, but requires manual adjustment of the RX internal delay to
>> work properly.
>>
>> The default RX delay provided by the driver is 1.95 ns, which proves to
>> be too high. Applying a 50% reduction seems to mitigate the issue.
>>
>> Also note this adjustment is not necessary on BeagleV Starlight SBC,
>> which uses a Microchip PHY. Hence, there is no indication of a
>> misbehaviour on the GMAC side, but most likely the issue stems from
>> the Motorcomm PHY.
>>
>> While at it, drop the redundant gpio include, which is already provided
>> by jh7100-common.dtsi.
>>
>> Co-developed-by: Emil Renner Berthing <emil.renner.berthing@xxxxxxxxxxxxx>
>> Signed-off-by: Emil Renner Berthing <emil.renner.berthing@xxxxxxxxxxxxx>
>> Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@xxxxxxxxxxxxx>
>> Reviewed-by: Jacob Keller <jacob.e.keller@xxxxxxxxx>
>> Reviewed-by: Andrew Lunn <andrew@xxxxxxx>
>> ---
>> .../jh7100-starfive-visionfive-v1.dts | 22 ++++++++++++++++++-
>> 1 file changed, 21 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/riscv/boot/dts/starfive/jh7100-starfive-visionfive-v1.dts b/arch/riscv/boot/dts/starfive/jh7100-starfive-visionfive-v1.dts
>> index e82af72f1aaf..4e396f820660 100644
>> --- a/arch/riscv/boot/dts/starfive/jh7100-starfive-visionfive-v1.dts
>> +++ b/arch/riscv/boot/dts/starfive/jh7100-starfive-visionfive-v1.dts
>> @@ -6,7 +6,6 @@
>>
>> /dts-v1/;
>> #include "jh7100-common.dtsi"
>> -#include <dt-bindings/gpio/gpio.h>
>>
>> / {
>> model = "StarFive VisionFive V1";
>> @@ -18,3 +17,24 @@ gpio-restart {
>> priority = <224>;
>> };
>> };
>> +
>> +/*
>> + * The board uses a Motorcomm YT8521 PHY supporting RGMII-ID, but requires
>> + * manual adjustment of the RX internal delay to work properly. The default
>> + * RX delay provided by the driver (1.95ns) is too high, but applying a 50%
>> + * reduction seems to mitigate the issue.
>> + *
>> + * It is worth noting the adjustment is not necessary on BeagleV Starlight SBC,
>> + * which uses a Microchip PHY. Hence, most likely the Motorcomm PHY is the one
>> + * responsible for the misbehaviour, not the GMAC.
>> + */
>> +&mdio {
>> + phy: ethernet-phy@0 {
>> + reg = <0>;
>> + rx-internal-delay-ps = <900>;
>> + };
>> +};
>> +
>> +&gmac {
>> + phy-handle = <&phy>;
>> +};
>
> Alphabetical ordering here, please.
Yeah, I wasn't sure if the ordering is more important than having the
referenced nodes added before. I suppose there's a need for v6. :-)
> /Emil
