Revision: 2.85

September 2012

Specification Update

15

5. Use of Wake on LAN Together with Manageability

Clarification: The Wakeup Filter Control Register (WUFC) contains the NoTCO bit, which affects the

behavior of the wakeup functionality when manageability is in use. Note that if

manageability is not enabled, the value of NoTCO has no effect.

When NoTCO contains the hardware default value of 0b, any received packet that

matches the wakeup filters will wake the system. This could cause unintended wakeups

in certain situations. For example, if Directed Exact Wakeup is used and the

manageability shares the host's MAC address, IPMI packets that are intended for the BMC

wake the system, which might not be the intended behavior.

When NoTCO is set to 1b, any packet that passes the manageability filter, even if it also

is copied to the host, is excluded from the wakeup logic. This solves the previous

problem since IPMI packets do not wake the system. However, with NoTCO=1b,

broadcast packets, including broadcast magic packets, do not wake the system since they

pass the manageability filters and are therefore excluded.

The Intel Windows* drivers set NoTCO by default.

If this is not the desired behavior, the EnableWakeOnManagmentOnTCO registry entry

can be used to change it starting with Intel LAN driver software release 15.5. Setting this

registry entry to 1b causes the driver to program NoTCO to 0b. A tool to modify the

registry entry can be provided.

Contact your Intel representative for access.

Workaround: N/A.

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6. Critical Session (Keep PHY Link Up) Mode Does Not Block All PHY Resets Caused by PCIe Resets

Clarification: D3 to D0 transition will cause a PHY reset even in Keep PHY Link Up mode. When Critical

Session Mode (Keep PHY Link Up) is enabled (via the NC-SI Set Intel Management

Control command or the SMBUS Management Control command), PCIe resets should not

cause a PHY reset. However, the following events will still cause a PHY reset:

•

Transition from D3 to D0 without general PCIe reset (i.e. PMCSR[1:0] changed from

11 to 00 by configuration write)

•

Function-level reset

Table 5. Effects of NoTCO

WoL Type

NoTCO

Shared MAC

Address

Unicast Packet

Broadcast Packet

Magic Packet

0b

-

OK

OK

Magic Packet

1b

Y

No wake

No wake

Magic Packet

1b

N

OK

No wake

Directed Exact

0b

Y

Wake even if MNG packet. No

way to talk to BMC without

waking host.

N/A

Directed Exact

0b

N

OK

N/A

Directed Exact

1b

-

OK

N/A