Negotiating a transmit wake time

• US 20100241880A1
• Filed: 03/17/2009
• Published: 09/23/2010
• Est. Priority Date: 03/17/2009
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Wertheimer, Aviad, Hays, Robert
• Granted Patent: US 8,201,005 B2
• Time in Patent Office: Days
• US Class Current: 713/310
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/3209 Monitoring remote activity, e.g. over telephone lines or network connections
• CPC Class Codes: Y02D 30/00 Reducing energy consumption in communication networks

Abstract

Includes receiving, from a link partner, a message specifying a link partner receive wake time and resolving to the lesser of the received link partner receive wake time and a local transmit wake time.

Claims

1. A method, comprising:

receiving, from a link partner, a message specifying a link partner receive wake time;

resolving to the lesser of the received link partner receive wake time and a local transmit wake time;

after sending a wake message to the link partner, delaying transmission of data destined for the link partner for at least the lesser of the link partner receive wake time and a local transmit wake time;

resuming transmission of data to the link partner after the lesser of the link partner receive wake time and a local transmit wake time.

2. The method of claim 1,

further comprising determining the local transmit wake time based on an amount of buffer to store data destined for the remote link partner;

and

wherein delaying transmission comprises buffering data destined for the remote link buffer.

3. The method of claim 1,

wherein the message further specifies a link partner transmit wake time;

and

further comprising determining a local receive wake time based, at least in part, on the wake time of a PHY.

4. The method of claim 3, wherein the determining the local receive wake time comprises determining based on a wake requirement of a one of a set of multiple power reduction modes.

5. The method of claim 1,

further comprising transmitting a frame to the link partner, the frame comprising a local transmit wake time and a local receive wake time.

6. The method of claim 1,

wherein the message comprises a link layer discovery protocol frame.

7. The method of claim 1,

further comprising transmitting an indication of a quiet/refresh ratio in an even numbered time slot of a link pulse.

8. The method of claim 1, wherein the receiving, the resolving, and the buffering comprises receiving, resolving, and buffering at a network interface controller, the network interface controller comprising a PHY, a media access controller, and a direct memory access (DMA) engine.

9. The method of claim 1, wherein the message further comprises a wake time for a PHY.

10. A system, comprising:

a network interface controller, the network interface controller comprising;

a PHY;

a media access controller;

a direct memory access engine; and

circuitry to

receive, from a link partner, a message specifying a link partner receive wake time;

resolving to the lesser of the received link partner receive wake time and a local transmit wake time;

delay transmission of data destined for the link partner for at least the lesser of the link partner receive wake time and a local transmit wake time;

resume transmission of the buffered data to the link partner after the lesser of the link partner receive wake time and a local transmit wake time.

11. The system of claim 10,

further comprising circuitry to store a local transmit wake time.

12. The system of claim 10,

wherein the PHY comprises circuitry to store a PHY transmit wait time.

13. The system of claim 10,

wherein the message further specifies a link partner transmit wake time.

14. The system of claim 10, wherein the determining the local receive wake time comprises determining based on requirements of one of a set multiple power reduction modes.

15. The system of claim 10,

further comprising circuitry to transmit a message to the link partner, the message comprising a local transmit wake time and a local receive wake time.

16. The system of claim 10,

wherein the message comprises a link layer discovery protocol frame.

17. The system of claim 10,

further comprising circuitry to transmit an indication of a quiet/refresh ratio of the PHY in an even numbered time slot of a link pulse.

18. The system of claim 10,

further comprising:

memory;

a processor; and

a power management unit, the power management unit to indicate to the network interface controller a wake period associated with a selected one of multiple power reduction modes.

19. The system of claim 18, wherein the power management unit enters a selected one of multiple power reduction modes based on the lesser of the received link partner receive wake time and a local transmit wake time

20. A method, comprising:

receiving, from a link partner, a message specifying a link partner transmit wake time;

resolving to the lesser of the received link partner transmit wake time and a local receive wake time;

after receiving a sleep message from the link partner, entering a system power saving mode based, at least in part, on the resolved lesser of the received link partner transmit wake time and a local receive wake time;

after receiving a wake message from the link partner, exiting the system power saving mode; and

receiving data from the link partner only after the resolved lesser of the link partner transmit wake time and a local receive wake time.

21. The method of claim 20,

further comprising notifying a system power management unit of the resolved lesser of the received link partner transmit wake time and a local receive wake time.

22. The method of claim 21,

wherein notifying the system power management unit comprises notifying after receiving the sleep message.