Re: [net-next,PATCH v2] enetc: Increase eMDIO MDC rate to 2.5 MHz

[Marek Vasut <marex@nabladev.com>]

On 10/8/26 4:34 AM, Wei Fang wrote:
>>>> Clark helped measure the MDC rate on the 95 EVK board this morning,
>>>> and the result was 644KHz, which is consistent with the theoretical
>>>> value. The scope's accuracy or other factors may be causing you to
>>>> observe a rate of 558kHz.
>>>
>>> That 644 kHz and 558 kHz differs too much to be an equipment
>>> miscalibration / misuse.
>>
>> For the sake of completeness, the MX95 B0 I have on my desk now prints this in
>> SM:
>>
>>   >$ clock.r
>> ...
>> 097: busnetcmix           =  on,  133333333Hz
>> 098: enet                 =  on,  666666666Hz
>> 099: enetphytest200m      =  on,   24000000Hz
>> 100: enetphytest500m      =  on,   24000000Hz
>> 101: enetphytest667m      =  on,   24000000Hz
>> 102: enetref              =  on,  250000000Hz
>> 103: enettimer1           =  on,   24000000Hz
>>
>> And the cycle time of MDC is 1.8ms , which is some 550 kHz .
> 
> The enet clock is the source of NETC system clock, and there is a 1/2
> divisor inside the NETCMIX, so the NETC system clock is 333 MHz.
> So the MDC clock should be 644 KHz, the frequency measured by
> Clark in the attachment is indeed 644kHz.
Is there maybe any other clock source that might feed the MDC clock on 
MX95 B0, that could explain the 558 kHz I observe ?

I apologize for my late reply, I am currently catching up on email.

Thank you for your help !