CRITICALITY

Low

DESCRIPTION

The DLR function is comprised of two separate functions that act together to implement DLR. The first is DLR packet detection and priority escalation. The second is DLR unicast address detection and packet forwarding.

DLR packet detection should correctly detect that a DLR packet with no VLAN, a single VLAN, or two VLAN’s has a DLR LTYPE. The packet should then be sent to the highest transmit FIFO priority of each destination egress port FIFO. In the case that the host port is the egress port, the packet should also be transferred to memory on the DLR channel.

DLR unicast address detection should match a unicast destination address and flood the packet to the VLAN minus the receive port and minus the host port. For a 3-port switch, a DLR unicast packet that is received (ingress) on an Ethernet port would be sent to the other Ethernet port. A DLR unicast packet that was received via the host port would be flooded to both Ethernet ports.

DLR cannot be enabled because the switch will enter an unknown state upon detection of a DLR packet. DLR unicast addresses can be added to the address table and will correctly flood to the VLAN minus the receive port and minus the host port. However, since DLR detection is dependent on enabling DLR (DLR_EN bit) and such enablement is precluded due to the bug, no DLR packet detection or priority escalation can occur.

WORKAROUND

None.

REVISIONS IMPACTED

AM574x SR 1.0
AM576x SR 1.0

AM574x: 1.0

DRA75xP, DRA74xP, DRA77xP, DRA76xP: 1.0

TDA2Px: 1.0

AM576x: 1.0