Re: [PATCH net-next v3 1/4] net: stmmac: Switch to zero-copy in non-XDP RX path

Andrew Lunn
2025-01-23T21:49:15Z

> Just to clarify, the patch that you had us try was not intended as an actual
> fix, correct? It was only for diagnostic purposes, i.e. to see if there is
> some kind of cache coherence issue, which seems to be the case? So perhaps
> the only fix needed is to add dma-coherent to our device tree?

That sounds quite error prone. How many other DT blobs are missing the
property? If the memory should be coherent, i would expect the driver
to allocate coherent memory. Or the driver needs to handle
non-coherent memory and add the necessary flush/invalidates etc.

Andrew