OpenOLT - BAL driver bug for downstream flows using same Vlan

Inconsistent internal error on adding a downstream flow in Broadcom BAL

The flow cannot be removed (the error says that it does not exist), the flow cannot be re-added(the error says that the svc_port is already in use). The flow is half added, the underlying tcont cannot be removed since it considers that a flow is still attached to it. The only way to clear this problem is to restart the BAL drivers

It seems to happen around one every 50 times. Tested with 8 ONUs rebooted repeatedly, the error happens around the 6 times on average

The problem seems to be linked to some multicast construct (bal_dpp_flow.c 1670| Error, bcm_multicast_ingress_add for pon failed -8), it fails sometimes but not all. It may be a synchronization/ race condition problem that act on the commands in the wrong order, or simultaneously on the same object.

Some logs of bal_core_dist are attached

A Broadcom CSP is openoed : CS6078762

A workaround was merged : VOL-1201