net/mlx5e: Don't create devices during unload flow
Running devlink reload command for port in switchdev mode cause
resources to corrupt: driver can't release allocated EQ and reclaim
memory pages, because "rdma" auxiliary device had add CQs which blocks
EQ from deletion.
Erroneous sequence happens during reload-down phase, and is following:
1. detach device - suspends auxiliary devices which support it, destroys
others. During this step "eth-rep" and "rdma-rep" are destroyed,
"eth" - suspended.
2. disable SRIOV - moves device to legacy mode; as part of disablement -
rescans drivers. This step adds "rdma" auxiliary device.
3. destroy EQ table - <failure>.
Driver shouldn't create any device during unload flows. To handle that
implement MLX5_PRIV_FLAGS_DETACH flag, set it on device detach and unset
on device attach. If flag is set do no-op on drivers rescan.
Fixes: a925b5e309c9 ("net/mlx5: Register mlx5 devices to auxiliary virtual bus") Signed-off-by: Dmytro Linkin <dlinkin@nvidia.com> Reviewed-by: Leon Romanovsky <leonro@nvidia.com> Reviewed-by: Roi Dayan <roid@nvidia.com> Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>