Re: [PATCH V3 2/3] dt-bindings: net: Fix Tegra234 MGBE PTP clock

[Jon Hunter <jonathanh@nvidia.com>]

On 25/03/2026 14:09, Krzysztof Kozlowski wrote:
> On 25/03/2026 15:07, Krzysztof Kozlowski wrote:
>> On 25/03/2026 14:58, Jon Hunter wrote:
>>> The PTP clock for the Tegra234 MGBE device is incorrectly named
>>> 'ptp-ref' and should be 'ptp_ref'. This is causing the following
>>> warning to be observed on Tegra234 platforms that use this device:
> 
>                             ^^^^^^^^^^^^^ Tegra234 (see further)
>>>
>>>   ERR KERN tegra-mgbe 6800000.ethernet eth0: Invalid PTP clock rate
>>>   WARNING KERN tegra-mgbe 6800000.ethernet eth0: PTP init failed
>>>
>>> Although this constitutes an ABI breakage in the binding for this
>>> device, PTP support has clearly never worked and so fix this now
>>> so we can correct the device-tree for this device. Note that the
>>
>> I don't understand that explanation.
>>
>> Driver dwmac-tegra.c: ptp-ref
>> Binding: ptp-ref
>> DTS: ptp-ref
>>
>> but you say that nothing was working correctly?
>>
>> Judging by these three - driver+binding+dts - obvious fix is no fix
>> because everything was fine, so please clarify the exact problem.
> 
> Correction - I missed in grep - there are ptp_ref users: tegra186 and
> tegra194, but how tegra234 could not work if it has correctly in DTS
> ptp-ref?

The problem lies in 
drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c which uses the 
name 'ptp_ref' which does not match 'ptp-ref'. This is where the warning 
is coming from. So basic ethernet does work, but stmmac_platform.c 
driver is complaining that the PTP clock is not found.

Yes Tegra186 and Tegra194 are not impacted by this, only Tegra234.

Jon

-- 
nvpublic