As explained in commit 9ffcc372 ("mlxsw: spectrum: Allow packets to
be trapped from any PG"), incoming packets can be admitted to the shared
buffer and forwarded / trapped, if:

(Ingress{Port}.Usage < Thres && Ingress{Port,PG}.Usage < Thres &&
 Egress{Port}.Usage < Thres && Egress{Port,TC}.Usage < Thres)
||
(Ingress{Port}.Usage < Min || Ingress{Port,PG} < Min ||
 Egress{Port}.Usage < Min || Egress{Port,TC}.Usage < Min)

Trapped packets are scheduled to transmission through the CPU port.
Currently, the minimum and maximum quotas of traffic class (TC) 0 of the
CPU port are 0, which means it is not usable.

Assign non-zero quotas to TC 0 of the CPU port, so that it could be
utilized by subsequent patches.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>