1 Reply Latest reply on Jan 27, 2017 4:54 PM by sophie

    Mgmt_class for MAD packet in MLX4 driver



      From the IB specification , MAD packet Mgmt_class values are defined in


      Table 113 Management Class Values


      ComMgt 0x07 Communication Management



      Subn 0x81 Subnet Management class (Directed route)

      The MAD data structure different for both Mgmt_classes.

      The Subn contains Extra data fields like hop_ptr, hop_cnt ... Defined in the ib_smp structure /include/rdma/ib_smi.h

      The ComMgt is for regular MAD data packets Defined in ib_mad_hdr /include/rdma/ib_mad.h

      when I receive MAD packets from Mellanox (mlx4) with rping. we are observing Mgmt_class as 0x07, But data offset as per Subn class.

      The  Mellnox driver  ( drivers/infiniband/hw/mlx4/main.c )  using ib_smp structure instead of ib_mad_hdr .

      Any reason for this ?