[PATCH net-next v2 3/3] net: stmmac: Set CIC bit only for TX queues with COE

[Jakub Kicinski]

On Thu, 21 Aug 2025 19:20:02 +0530 G Thomas, Rohan wrote:
> > To be clear -- this is just for context. I don't understand the details
> > of what the CIC bit controls, so the final decision is up to you.  
> 
> Currently, in the stmmac driver, even though tmo_request_checksum is not
> implemented, checksum offloading is still effectively enabled for AF_XDP
> frames, as CIC bit for tx desc are set, which implies checksum
> calculation and insertion by hardware for IP packets. So, I'm thinking
> it is better to keep it as false only for queues that do not support
> COE.

Oh, so the device parses the packet and inserts the checksum whether
user asked for it or not? Damn, I guess it may indeed be too late
to fix, but that certainly _not_ how AF_XDP is supposed to work.
The frame should not be modified without user asking for it..