US 12,461,871 B2
Device control block scan for channel recovery actions
Robert Edward Galbraith, Rochester, MN (US); Martin Taubert, Gaertringen (DE); Jana Christine Migge, Aidlingen (DE); and Francis Gassert, Monroe, NY (US)
Assigned to International Business Machines Corporation, Armonk, NY (US)
Filed by International Business Machines Corporation, Armonk, NY (US)
Filed on Jul. 25, 2023, as Appl. No. 18/358,730.
Prior Publication US 2025/0036586 A1, Jan. 30, 2025
Int. Cl. G06F 13/20 (2006.01)
CPC G06F 13/20 (2013.01) [G06F 2213/40 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A method comprising:
identifying, by a processor, a set of channels to be recovered that are associated with the processor;
creating, by the processor, a Device Control Block (DCB) Bit Array comprising a plurality of DCBs for each channel in the set of channels;
transmitting the DCB Bit Array to the processor to process channel recovery to reset and start the set of the channels;
issuing, by the processor, a poll for a channel communication area (CCA) command sequence to determine channel recovery actions for recovering the set of channels;
based on the CCA command sequence, performing, by the processor, synchronous DCB scan recovery by sequentially scanning an incremental portion of the DCB Bit Array to determine a status of the DCBs in the incremental portion of the DCB Bit Array along with modifying, by the processor, the DCBs in the incremental portion based on the channel recovery actions by asynchronous CCA recovery processing to update the DCBs;
responsive to completing the synchronous DCB scan, implementing, by the processor, any remaining recovery actions for each of the DCBs in the incremental portions of the DCB Bit Array; and
starting, by the processor, each channel of the set of channels with the updated DCBs.