Broadcom TH5: Enable pfcwd hardware deadlock detection and recovery using SAI_QUEUE_ATTR_ENABLE_PFC_DLDR

[pinky-nexthop]

Tomahawk 5 supports HW based PFC Deadlock detection and recovery. This can be enabled by programming SAI_QUEUE_ATTR_ENABLE_PFC_DLDR SAI attribute.

This issue tracks the addition of SAI_QUEUE_ATTR_ENABLE_PFC_DLDR support in orchagent.

[bingwang-ms]

Hi @pinky-nexthop, may I know what issue you saw without setting SAI_QUEUE_ATTR_ENABLE_PFC_DLDR? Per my test, PFC detection is still working by checking counters with lua script. The issue I saw is not all actions (such as DROP, FORWARD, and etc.) are supported.

[pinky-nexthop]

Hi @pinky-nexthop, may I know what issue you saw without setting SAI_QUEUE_ATTR_ENABLE_PFC_DLDR? Per my test, PFC detection is still working by checking counters with lua script. The issue I saw is not all actions (such as DROP, FORWARD, and etc.) are supported.

The issue is that without SAI_QUEUE_ATTR_ENABLE_PFC_DLDR, hardware doesn't detect the deadlock and therefore, setting SAI_QUEUE_ATTR_PFC_DLR_INIT does no recovery on the queue.

You are right, that lua scripts can detect the storm but the correct recovery actions don't take place. For SAI_QUEUE_ATTR_PFC_DLR_INIT to recover the queue, SAI_QUEUE_ATTR_ENABLE_PFC_DLDR is a pre-requisite.

[bingwang-ms]

@kperumalbfn FYI.