NEGOTIATING A TRANSMIT WAKE TIME

• US 20160378159A1
• Filed: 08/14/2016
• Published: 12/29/2016
• 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 10,386,908 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 a transmit wake time based on the received link partner receive wake time and a local transmit wake time;

receiving a request to transmit data to the link partner; and

after sending a wake signal to the link partner, waiting for at least the transmit wake time to delay transmitting data to the link partner.

2. The method of claim 1, further comprising:

determining the local transmit wake time based on transmit buffer space available for transmitting data to the remote link partner; and

wherein waiting for at least the transmit wake time to delay transmitting data to the link partner includes buffering data destined for the remote link buffer.

3. The method of claim 1,

the message further specifies a link partner transmit wake time;

and

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

4. The method of claim 3, 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, comprising:

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

6. The method of claim 1, the message comprises a link layer discovery protocol frame.

7. The method of claim 1, comprising:

periodically receiving, from the link partner, refresh signals during a low power mode of the link partner; and

performing timing recovery and coefficient updating responsive to each received refresh signal.

8. The method of claim 2, receiving the message, resolving to the transmit wake time, and buffering data comprises receiving, resolving, and buffering at a network interface controller, the network interface controller including a PHY, a media access controller, and a direct memory access (DMA) engine.

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

11. The system of claim 1, further comprising the logic to:

determine the local transmit wake time based on transmit buffer space available to transmit data to the remote link partner; and

wherein to wait for at least the transmit wake time to cause a delay to transmission of data to the link partner includes causing data destined for the remote link buffer to be buffered in the transmit buffer.

10. A system, comprising:

a network interface controller, the network interface controller including;

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;

resolve to a transmit wake time based on the received link partner receive wake time and a local transmit wake time;

receive a request to transmit data to the link partner;

send a wake signal to the link partner; and

wait for at least the transmit wake time to cause a delay to transmission of data to the link partner.

12. The system of claim 10, further comprising the circuitry to store a local transmit wake time.

13. The system of claim 10, further comprising the circuitry to store a PHY transmit wake value for the PHY.

14. The system of claim 13, comprising:

the message to further indicate a link partner transmit wake time; and

the circuitry to determine a local receive wake time based, at least in part, on the PHY transmit wake value.

15. The system of claim 14, comprising:

the circuitry to determine the local receive wake time based on requirements of one of a set multiple power reduction modes.

16. The system of claim 10, further comprising the circuitry to transmit a message to the link partner, the message including a local transmit wake time and the local receive wake time.

17. The system of claim 10, the message comprises a link layer discovery protocol frame.

18. The system of claim 10, further comprising the circuitry to:

periodically receive, from the link partner, refresh signals during a low power mode of the link partner; and

perform timing recovery and coefficient updating responsive to each received refresh signal.

19. 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.

20. The system of claim 18, the power management unit enters a selected one of multiple power reduction modes based on the transmit wake time.

24. The method of claim 10, further comprising:

periodically receiving, from the link partner, refresh signals while in the system power saving mode; and

performing timing recovery and coefficient updating responsive to each received refresh signal.

21. A method, comprising:

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

resolving to a transmit wake time based on 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 receive wake time;

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

receiving data from the link partner no sooner than the resolved receive wake time.

22. The method of claim 21, further comprising:

notifying a system power management unit of the resolved transmit wake time.

23. The method of claim 22, notifying the system power management unit comprises notifying after receiving the sleep message.