Method for handling unexpected completion packets and completion packets with a non-successful completion status

• US 20030174716A1
• Filed: 12/28/2001
• Published: 09/18/2003
• Est. Priority Date: 12/28/2001
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Ajanovic, Jasmin, Harriman, David, Creta, Kenneth C., Lee, David M., Solomon, Gary
• Granted Patent: US 7,184,399 B2
• Time in Patent Office: Days
• US Class Current: 370/401
• CPC Class Codes: G06F 13/4282 on a serial bus, e.g. I2C bus, SPI bus on daisy chain buses G06F13/4247
• CPC Class Codes: G06F 2213/0026 PCI express

Abstract

A requesting device and a completer device are coupled via a high-speed serial interface within a computer system. The requesting device transmits a packet for a request transaction to a completer device. The completer device checks for error conditions in the course of servicing the request. If an error condition is found then the completer device transmits a completion packet with a completion status of something other than successful. The completion packet includes a completer identification field. The requesting device records the completer identification value and indicates in a register that a completion packet has been received with a non-successful completion status.

Claims

1. A method, comprising:

receiving a completion packet at a receiving device;

determining whether the completion packet is expected by the receiving device; and

discarding the completion packet if the completion packet is not expected.

2. The method of claim 1, wherein determining whether the completion packet is expected includes determining whether the completion packet corresponds to any outstanding requests previously issued by the receiving device.

3. The method of claim 2, further comprising reporting an error condition.

4. A method, comprising:

receiving a completion packet at a receiving device, the completion packet including a completion status and a completer identification;

determining whether the completion packet includes a completion status other than successful; and

storing the completer identification in a first register if the completion status is other than successful.

5. The method of claim 4, further including indicating in a second register that an unsuccessful completion was received if the completion status is other that successful.

6. The method of claim 5, further comprising reporting an error condition if the completion status is other than successful.

7. A method, comprising:

servicing a request packet from a requesting device at a completer device, the request packet including a requester identification and a tag;

transmitting a completion packet with a completion status other than successful from the completer device to the requesting device if an error condition exists; and

storing the requestor identification at a location in the completer device if the error condition exists.

8. The method of claim 7, further comprising storing the tag at a location in the completer device if the error condition exists.

9. The method of claim 8, further comprising indicating in a register in the completer device that a completion packet with a completer status other than successful was transmitted if the error condition exists.

10. The method of claim 9, further comprising reporting the error condition if it exists.