On Tue, 8 Oct 2024 12:38:18 -0700 Michael Chan wrote: > > Where does the min value of 64 come from? Ethernet min frame length? > > The length is actually the ethernet length minus the 4-byte CRC. So > 60 is the minimum length that the driver will see. Anything smaller > coming from the wire will be a runt frame discarded by the chip. Also for VF to VF traffic? > > IIUC the copybreak threshold is purely a SW feature, after this series. > > If someone sets the copybreak value to, say 13 it will simply never > > engage but it's not really an invalid setting, IMHO. Similarly setting > > it to 0 makes intuitive sense (that's how e1000e works, AFAICT). > > Right, setting it to 0 or 13 will have the same effect of disabling > it. 0 makes more intuitive sense. Agreed on 0 making sense, but not sure if rejecting intermediate values buys us anything. As Andrew mentioned consistency is important. I only checked two drivers (e1000e and gve) and they don't seem to check the lower limit.
