Re: [PATCH net v2] net: macb: rate limit netdev error info print in the data path

[Nicolai Buchwitz <nb@tipi-net.de>]

Hi

On 4.10.2026 15:40, taozj888 wrote:
> Hello Theo, Nicolai:
> 
> Please see answer inline.

> [...]

>>>> Fixes: 89e5785fc8a6 ("[PATCH] Atmel MACB ethernet driver")
>>> 
>>> IMHO the correct tag is 4df95131ea80 ("net/macb: change RX path for
>>> GEM")?
>>> At least the gem_rx() messages were introduced here.
>> 
>> The patch used to touch macb_start_xmit(), which explains why I told
>> Zijin to target the initial commit on previous revision.
>> 
> OK, I will still use the initial commit indicated by Theo.

Please re-read Théo's reply: he only suggested the initial
because v1 also touched macb_start_xmit(). v2 doesn't anymore,
89e5785fc8a6 is no longer the right target. Please use:

Fixes: 4df95131ea80 ("net/macb: change RX path for GEM")

> [...]

>>> This will just hide the error message, but the split/drop is still
>>> present.
>>> How about limiting JML in macb_init_hw() properly?
>>> 
>>>          if ((bp->caps & MACB_CAPS_JUMBO) && bp->jumbo_max_len) {
>>>                  u32 jml = bp->rx_buffer_size - NET_IP_ALIGN +
>>> ETH_FCS_LEN;
>>>                  gem_writel(bp, JML, min(jml, bp->jumbo_max_len));
>>>          }
>>> 
>>> The code above is untested, so probably needs further tweaking. An
>>> alternative could
>>> be to handle the split frames in gem_rx() correctly.
>> 
>> I agree with you but to clarify for Zijin: if you do this then it 
>> should
>> be a separate patch as changes are pretty unrelated.
> 
> Yes, with your experience in this area, maybe a separate patch for it 
> is preferred.
> I think the error reported is not just related the Jumbo frame, but the 
> jumbo frame
> would trigger the error. So rate limit printing this kind of msg is 
> needed but not
> totally hide those msgs.

Which other cases do you have in mind?

Rate limiting the message in this patch is fine with me. I can look
into the JML patch separately, or you can give it a try.

> [...]

Thanks,
Nicolai