Re: [PATCH] net: dsa: qca8k: Disable mgmt Ethernet for qca8327

[Andrew Lunn <andrew@lunn.ch>]

On Mon, Aug 10, 2026 at 08:15:53AM +0200, Michał Kępień wrote:
> While the qca8327 switch appears to support in-band mgmt Ethernet,
> prolonged use of that protocol (e.g. for polling link state) makes the
> device unstable: within minutes, ports randomly go down and no traffic
> is forwarded anymore.  The same issues do not occur when MDIO is used
> exclusively, so ensure mgmt Ethernet is not used on the qca8327.

Do you have time to narrow down the cause?

I _think_ in band management is used for a few different
things. e.g. statistics, as you said, PHY polling etc. Rather than
turning everything off, could you try just doing PHY polling via MDIO,
but statistics via ethernet, and do an ethtool -S every so often to
see if you can trigger the problem.

Could you also check if the management packets are getting lost? Look
at the results from wait_for_completion_timeout(), is it timing out?
If so, is the retry mechanism working? When i added the Marvell
equivalent for in-band signalling i got the retry mechanism wrong, but
never noticed because i was not loosing packets.

Thanks
	Andrew