WAX610 - 802.3at stopped working

Finally manage to resolve it.

1. As per page 225 of switch manual, The power stateful control TLV is defined in IEEE P802.3at D1.0. The later versions no longer support this TLV. HP devices send this type of TLVs only after receiving them.

2. As per HP knowledge base number emr_na-kc0103319en_us, If the PD is for 802.3at, switch can communicate with the PD using LLDP.

3. Issue is switch waits for OD (WAX610) to ask for more power however WAX610 waits for switch to give more power. so there is deadlock.

4. This deadlock can be broken by overloading PD so it request more power from switch. This was the case when I first install WAX610 because I've only one WAX610, later I added another one.

5. This time after update, there was not enough load. So as per point 2, I enabled LLDP which is not required for a single location. It sets following:
Power port class : PSE
PSE power supported : Yes
PSE power enabled : Yes
PSE pairs control ability : No
Power pairs : Signal
Port power classification : Class 4
Power Type : Type 2 PSE
Power Source : Primary
Power Priority : Critical
PD requested power value : 25.5(W)
PSE allocated power value : 25.5(W)

So problem was solved by enabling LLDP. But it can be solved by loading enough clients on WAX610 too.