ACK: [SRU][J/N:linux-bluefield][PATCH v1 0/1] mlxbf_gige: interface defaults to ALLMULTI mode

[Gabriela Bittencourt]

On 5/6/26 11:20, David Thompson wrote:
> BugLink: https://bugs.launchpad.net/bugs/2151223
>
> SRU Justification:
>
> [Impact]
>
> Today, the mlxbf_gige driver's "open()" routine calls "enable_multicast_rx()"
> and leaves the OOB_RX_MAC_FILTER_MULTICAST register (offset 0x0570) at its
> default data/mask values. In this default state, the GIGE interface operates
> in ALLMULTI mode, so all frames with a destination multicast MAC address pass
> through the hardware receive filter. If the network connected to oob_net0 has
> lots of multicast traffic not intended for local termination to the BlueField
> then driver resources are consumed handling these packets, and in extreme
> cases can result in receive drops at driver level.
>
> [Fix]
>
> The fix updates the logic in the driver's "ndo_set_rx_mode()", which now
> programs the hardware receive filters based on the multicast MAC addresses
> configured by the stack. The new implementation can support up to three
> multicast MAC addresses using two direct-match RX filters and a 48-bit
> start/end range. If the stack attempts to configure more than 3 multicast
> MAC addresses, then the interface will be programmed in ALLMULTI mode.
>
> [Test Case]
>
> * Boot BF3 and verify configured multicast MACs via "ip maddr show oob_net0"
> * Perform traffic tests to that set of multicast MAC:
>    a) If number of multicast MACs <= 3, then only multicast traffic to those MACs
>       should be permitted
>    b) If the number of multicast MACs > 3, then the oob_net0 interface is in
>       ALLMULTI mode and will allow all multicast traffic
>
> [Regression Potential]
>
> Low risk, but could potentially impact handling of multicast traffic
>
> David Thompson (1):
>    UBUNTU: SAUCE: mlxbf_gige: update hardware receive filter config for multicast MACs
>
>   .../ethernet/mellanox/mlxbf_gige/mlxbf_gige.h |  14 ++-
>   .../mellanox/mlxbf_gige/mlxbf_gige_main.c     |   3 +-
>   .../mellanox/mlxbf_gige/mlxbf_gige_regs.h     |   2 +
>   .../mellanox/mlxbf_gige/mlxbf_gige_rx.c       | 104 ++++++++++++++++--
>   4 files changed, 108 insertions(+), 15 deletions(-)
>
Acked-by: Gabriela Bittencourt <gabriela.bittencourt at canonical.com>