Re: [PATCH v5 net-next 05/10] net: switchdev: pass flags and mask to both {PRE_,}BRIDGE_FLAGS attributes

[Grygorii Strashko]

On 12/02/2021 17:15, Vladimir Oltean wrote:
> From: Vladimir Oltean <vladimir.oltean@xxxxxxx>
>
> This switchdev attribute offers a counterproductive API for a driver
> writer, because although br_switchdev_set_port_flag gets passed a
> "flags" and a "mask", those are passed piecemeal to the driver, so while
> the PRE_BRIDGE_FLAGS listener knows what changed because it has the
> "mask", the BRIDGE_FLAGS listener doesn't, because it only has the final
> value. But certain drivers can offload only certain combinations of
> settings, like for example they cannot change unicast flooding
> independently of multicast flooding - they must be both on or both off.
> The way the information is passed to switchdev makes drivers not
> expressive enough, and unable to reject this request ahead of time, in
> the PRE_BRIDGE_FLAGS notifier, so they are forced to reject it during
> the deferred BRIDGE_FLAGS attribute, where the rejection is currently
> ignored.
>
> This patch also changes drivers to make use of the "mask" field for edge
> detection when possible.
>
> Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>
> ---
> Changes in v5:
> Rebased on top of AM65 CPSW driver.
>
> Changes in v4:
> Patch is new.
>
>   .../marvell/prestera/prestera_switchdev.c     | 23 +++++----
>   .../mellanox/mlxsw/spectrum_switchdev.c       | 50 +++++++++++--------
>   drivers/net/ethernet/rocker/rocker_main.c     | 10 ++--
>   drivers/net/ethernet/ti/am65-cpsw-switchdev.c | 24 +++++----
>   drivers/net/ethernet/ti/cpsw_switchdev.c      | 24 +++++----
>   drivers/staging/fsl-dpaa2/ethsw/ethsw.c       | 34 ++++++++-----
>   include/net/switchdev.h                       |  7 ++-
>   net/bridge/br_switchdev.c                     |  6 +--
>   net/dsa/dsa_priv.h                            |  6 ++-
>   net/dsa/port.c                                | 34 +++++++------
>   10 files changed, 129 insertions(+), 89 deletions(-)

Reviewed-by: Grygorii Strashko <grygorii.strashko@xxxxxx>

--
Best regards,
grygorii