[PATCH] net: macb: add TX stall timeout callback to recover from lost TSTART write

[Andrea della Porta]

Hi Nicolai,

On 14:53 Fri 12 Jun     , Nicolai Buchwitz wrote:
> Hi Andrea
> 
> On 12.6.2026 14:51, Andrea della Porta wrote:
> 
> > [...]
> 
> > > 
> > > The commit message describes it as RP1 specific, but it gets applied
> > > to all
> > > other variants?
> > 
> > I've seen this issue happening only on RaspberryPi 5, but AFAIK it
> > could affect also other MACB blocks connected through PCIe, so it
> > may be widespread (even though it should have probably already been
> > noticed in the past). In the orginal driver there's no timeout callback
> > defined and this is much like pretgending the issue causing the timeout
> > to happen to go away without doing anything (whatever the cause ot the
> > specific hw are). So in my opinion we can just extend that to all MACB.
> > Or maybe we should execute the restart conditionally on
> > .compatible = "raspberrypi,rp1-gem"?
> 
> I just observed the issue once, but other people reported it to be happen
> more
> frequently. If we can narrow down a reproducer, it would be good to test on
> other
> blocks too (like EyeQ at Théo's).|
> 
> So maybe you can imagine a good repro for this issue?

Sure, it's happening quite often during bulk dataflow, at least
on my RPi5.
It can be reproduced with the following, issued from the DUT:

  iperf -c <SERVER_IP> -P 10 -t 3000 -w 4M -i 1

plus, of course, the related command on server side: iperf -s.

It usually happens a couple of times withing a few hours.

Regards,
Andrea

> 
> Thanks,
> Nicolai