TCP/IP LCS (PCCA) Device Driver Can Incorrectly Initialize
Causing Multiple Unpredictable Results

 
 APAR Identifier ...... PQ36325      Last Changed ........ 00/11/01
 TCP/IP LCS (PCCA) DEVICE DRIVER CAN INCORRECTLY INITIALIZE
 CAUSING MULTIPLE UNPREDICTABLE RESULTS
 
 Symptom ...... IN INCORROUT         Status ........... CLOSED  PER
 Severity ................... 3      Date Closed ......... 00/06/01
 Component .......... 5735FAL00      Duplicate of ........
 Reported Release ......... 240      Fixed Release ............ 999
 Component Name TCP/IP V2 FOR V      Special Notice
 Current Target Date ..              Flags
 SCP ...................
 Platform ............
 
 Status Detail: ASSIGNMENT - APAR has been assigned to a
                             programmer.
 
 PE PTF List:
 
 PTF List:
 Release 240   : UQ43919 available 00/06/14 (1000 )
 Release 310   : UQ43920 available 00/06/14 (0002 )
 Release 320   : UQ43921 available 00/06/14 (0002 )
 
 Parent APAR:    PQ28164
 Child APAR list:
 
 ERROR DESCRIPTION:
 TCP/IP LCS device driver fails to correctly process asynchronous
 I/O interrupts.  This eventually causes the device driver in
 question to become "out of sync", after which incoming read
 interrupts are lost.  The "out of sync" condition can arise
 under many different conditions.
 
 This APAR has been opened to address the problems in the VM/ESA
 environment which are similar to those reported by MVS APAR
 PQ28164.
 
 LOCAL FIX:
 Issue separate OBEYFILE commands to STOP, and then (re) START
 the device in question.
 
 PROBLEM SUMMARY:
 ****************************************************************
 * USERS AFFECTED: All users of VM TCP/IP LCS devices           *
 ****************************************************************
 * PROBLEM DESCRIPTION: LCS device errors at start up.          *
 ****************************************************************
 * RECOMMENDATION: APPLY PTF                                    *
 ****************************************************************
 During LCS device startup an attention interrupt is received
 from the device when a response to a read is expected. The LCS
 device driver interprets this async attention as ending status
 to the previously-issued read, and may miscompare on expected
 data (as the read command may not truly be completed at this
 point).
 The loss of the original read's data to the sense data routine
 prevents the successful initialization of the device.
 Stopping and re-starting the device may re-sync it.
 
 PROBLEM CONCLUSION:
 ToPcca3() in TCTOPC3 is changed to ignore device end or
 attention interrupt until device is started.
 
 TEMPORARY FIX:
 
 COMMENTS:
 
 MODULES/MACROS:   TCPIP    TCTOPC3
 
 SRLS:      NONE
 
 RTN CODES:
 
 CIRCUMVENTION:
 
 MESSAGE TO SUBMITTER: