Re: [PATCH v2] net: macb: add TX stall timeout callback to recover from lost TSTART write

[Andrea della Porta]

Hi Theo,

On 17:07 Tue 16 Jun     , Théo Lebrun wrote:
> Hello Andrea,
> 
> On Tue Jun 16, 2026 at 3:23 PM CEST, Andrea della Porta wrote:
> > From: Lukasz Raczylo <lukasz@xxxxxxxxxxx>
> >
> > The MACB found in the Raspberry Pi RP1 suffers from sporadic stalls on
> > the TX queue.
> > While the exact root cause is not yet fully understood, it is likely
> > related to a hardware issue where a TSTART write to the NCR register
> > is missed, preventing the transmission from being kicked off.
> >
> > Implement a timeout callback to handle TX queue stalls, triggering the
> > existing restart mechanism to recover.
> >
> > Link: https://lore.kernel.org/all/20260514215459.36109-1-lukasz@xxxxxxxxxxx/
> > Fixes: dc110d1b23564 ("net: cadence: macb: Add support for Raspberry Pi RP1 ethernet controller")
> > Signed-off-by: Lukasz Raczylo <lukasz@xxxxxxxxxxx>
> > Co-developed-by: Steffen Jaeckel <sjaeckel@xxxxxxx>
> > Signed-off-by: Steffen Jaeckel <sjaeckel@xxxxxxx>
> > Co-developed-by: Andrea della Porta <andrea.porta@xxxxxxxx>
> > Signed-off-by: Andrea della Porta <andrea.porta@xxxxxxxx>
> 
> Thanks for this V2.
> 
> Reviewed-by: Théo Lebrun <theo.lebrun@xxxxxxxxxxx>
> 
> Any news from the Raspberry Pi community about this bug investigation?

Not from my side, unfortunately.

Regards,
Andrea

> 
> Thanks,
> 
> --
> Théo Lebrun, Bootlin
> Embedded Linux and Kernel engineering
> https://bootlin.com
>