CPSW: IET express traffic policing issue
Details:
This applies to 9-port CPSW, 5-port CPSW, 3-port CPSW, and 2-port CPSW IET
traffic.
In IET (Interspersed Express traffic), if a preempted packet was interrupted by an
express packet, two things can occur:
- If the express traffic is policed, the frame size for the preempted packets
is applied to the express traffic policer. Assuming a policer was set up to
rate schedule an express traffic stream, it would take a hit by the
preempted packet size it interrupted. The preempted packet also takes on the
express traffic policer status. As a result, preempted packets could get
dropped along with other express traffic due to the express traffic
policer.
- If the express traffic was not policed, the interrupted preempt packet would
not get its packet size applied to the preempted policer.
Workaround(s):
Do not police IET express traffic.