Browse Prior Art Database

Parallel Adapter Recovery Action Decode

IP.com Disclosure Number: IPCOM000124373D
Original Publication Date: 2005-Apr-18
Included in the Prior Art Database: 2005-Apr-18
Document File: 2 page(s) / 35K

Publishing Venue

IBM

Abstract

A program is disclosed to enhance the host adapter interrupt decoding and handling procedures. This new approach uses a table to classify all the adapter interrupts based on its priority to invoke the proper recovery actions. The new method to handle the interrupt decoding process will reduce the time to code and to debug the errors. The code is more reusable making it easier to support error recovery for new adapter.

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Parallel Adapter Recovery Action Decode

The current adapter interrupt handling procedure sequentially decodes each interrupt bit in the Interrupt Register and attempts to reset the error and initiate a recovery action based on the specific error. This method of sequential decoding made it very difficult and error prone to change the sequence of error decode and handling to reflect the priority of the error. In addition it was difficult to quickly identify, or modify a particular error class because the error decode spanned several functions. As a result the error handling support for new adapters was very difficult., in fact the error handling code had to be completely rewritten for each new adapter. This takes time, is error prone and yields code that is hard to maintain.

The new adapter interrupt handling process uses an interrupt decoding table to decode and reset each specific error. The table is organized by priority so that the most severe errors are decoded first and recovered. The recovery actions are structured so that the higher priority recovery is sufficient to recover lower priority errors. When an error register matches a error register mask, no further decode is required. This approach makes it possible to quickly reclassify an error, change its priority or its recovery path by simply changing a table entry. The invention improves the error recovery process. It also helps developer to shorten the time to isolate, identify and correct a problem In a...