Tracking deferred data transfers on a system-interconnect bus
View Patent ↗Systems and techniques to track deferred data transfers on a system-interconnect bus. A deferral response initiates storage of information corresponding to the response and tracking of progress for a requested data transfer. A master device, such as a bus adapter, may include a split-transaction repository, timers, and a split-transaction monitor. The master device may include both hardware and firmware components, and may be designed to handle split responses as defined by a Peripheral Component Interconnect Extended standard.
1. A method comprising:
sending a request to transfer data on a system-interconnect bus;
receiving a response on the system-interconnect bus to the data-transfer request, the response indicating an acknowledgment of the data-transfer request and a commitment to respond to the data-transfer request at a later time;
saving information corresponding to the data-transfer request;
tracking progress for the requested data transfer; and
identifying a transfer error if the data-transfer progress fails to meet predefined criteria.
2. The method of claim 1 , wherein said tracking progress comprises:
initiating a timer upon receipt of the response; and
resetting the timer and updating the data-transfer information upon receipt of a portion of the data.
3. The method of claim 2 , wherein the data-transfer information comprises an address, a data count and a data-transfer identifier.
4. The method of claim 3 , wherein the system-interconnect bus comprises a Peripheral Component Interconnect Extended bus.
5. The method of claim 4 , further comprising modifying tag generation in response to an identified transfer error.
6. The method of claim 5 , wherein the predefined criteria comprise two timeouts of the timer without a change in the data-transfer information.
7. The method of claim 6 , wherein modifying tag generation comprises updating a tag offset.
8. The method of claim 7 , further comprising:
monitoring identified transfer errors to identify a system error.
9. The method of claim 8 , wherein monitoring identified transfer errors comprises tracking the identified transfer errors to determine when a portion of memory generates a series of transfer errors.
10. A machine-implemented method comprising:
sending a request to transfer data on a parallel bus that supports multiple concurrent data transfers identified by generated data-transfer identifiers;
receiving a response on the parallel bus to the data-transfer request, the response indicating an acknowledgment of the data-transfer request and a commitment to respond to the data-transfer request at a later time;
saving address and data count information corresponding to the data-transfer request;
initiating a timer;
resetting the timer and updating the address and data count information upon receipt of a portion of the data;
identifying a transfer error when the timer times out;
modifying data-transfer identifier generation for transactions in response to an identified transfer error; and
monitoring identified transfer errors to identify a system error.
11. The method of claim 10 , wherein identifying a transfer error comprises identifying a transfer error when the timer times out without a change in the address and data count information since a previous occurrence of the timer timing out.
12. The method of claim 11 , wherein modifying data-transfer identifier generation comprises updating an offset.
13. The method of claim 12 , wherein monitoring identified transfer errors comprises tracking the identified transfer errors to determine when a portion of memory generates a series of transfer errors.
14. The method of claim 13 , wherein the parallel bus comprises a bus conforming to a Peripheral Component Interconnect Extended standard.
15. A machine-readable medium embodying information indicative of instructions for causing a device to perform operations comprising:
receiving a timeout notice for a bus sequence that began with a split transaction;
identifying a transfer error evidenced by delay in completion of the sequence; and
modifying sequence identifier generation in response to an identified transfer error.
16. The machine-readable medium of claim 15 , wherein the bus sequence conforms to a Peripheral Component Interconnect Extended bus standard.
17. The machine-readable medium of claim 16 , wherein delay in completion of the sequence comprises a timeout of a hardware timer tracking progress for the sequence.
18. The machine-readable medium of claim 16 , wherein the operations further comprise:
monitoring identified transfer errors to identify a system error.
19. The machine-readable medium of claim 18 , wherein monitoring identified transfer errors comprises tracking the identified transfer errors to determine when a portion of memory generates a series of transfer errors.