In 82599, for a Jumbo packet of 9.5 K ( which consumes 5 descriptors of 2048 bytes each ), when does the Descriptor write back happen ? Does it happen per Descriptor or once per aggregated Descriptors ? Is it possible that all descriptors except last one to be written back and when you read RDH register, I get the last pending descriptor waiting inside 82599. We are using srrctl |= IXGBE_SRRCTL_DESCTYPE_ADV_ONEBUF;
In my setup, I am seeing that, I don't see EOP set even when I read 5 descriptors. Checking DD will return me an incomplete packet. What should I do in such a case ? References from Data sheet: -> Checking through DD bits eliminates a potential race condition: all descriptor data is posted internally prior to incrementing the head register and a read of the head register could potentially pass the descriptor waiting inside the 82599. Regards, Kaushal _______________________________________________ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "freebsd-hackers-unsubscr...@freebsd.org"
