[PATCH net v2 1/1] net: stmmac: Prevent DSA tags from breaking COE on stmmac

[Romain Gantois]

Hi Florian,

On Tue, 2 Jan 2024, Florian Fainelli wrote:

...
> > Fixes: 6b2c6e4a938f ("net: stmmac: propagate feature flags to vlan")
> > Cc: stable at vger.kernel.org
> > Reported-by: Richard Tresidder <rtresidd at electromag.com.au>
> > Closes:
> > https://lore.kernel.org/netdev/e5c6c75f-2dfa-4e50-a1fb-6bf4cdb617c2@electromag.com.au/
> > Reported-by: Romain Gantois <romain.gantois at bootlin.com>
> > Closes:
> > https://lore.kernel.org/netdev/c57283ed-6b9b-b0e6-ee12-5655c1c54495@bootlin.com/
> 
> Fairly sure those should be Link: and Closes: should be used for bug tracker
> entries.

ACK

> > +	return (proto == htons(ETH_P_IP)) || (proto == htons(ETH_P_IPV6)) ||
> > +		(proto == htons(ETH_P_8021Q));
> 
> Do you need to include ETH_P_8021AD in that list as well or is not stmmac
> capable of checksuming beyond a single VLAN tag?

The datasheet for my Ethernet controller doesn't mention 802.1ad tag 
handling and I ran some loopback tests that showed that this controller doesn't 
recognize 802.1ad frames as vlan frames. I also haven't seen anything in the 
stmmac driver that suggests that 802.1ad offloading is supported. Maybe the 
stmmac maintainers could weigh in on this?

Best Regards,

-- 
Romain Gantois, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com