OA48196: IST1222I XXXX DEVICE XXXX IS INOPERATIVE WHEN MPC IS ACTIVATED.

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• IST1222I XXXX DEVICE XXXX IS INOPERATIVE WHEN MPC IS ACTIVATED.
  CCW trace showed that after y-side XID0 channel program was
  issued - interrupt with Channel End, Device End occurred, then
  Attention interrupt.  These were passed to VTAM in reverse
  order - attention routine (with attn), then Channel End
  routine with CE,DE.  Attention routine did not properly
  remember that the attn had occurred - so no XID7 channel program
  was started.
  Additional Symptoms: IST259I
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * All using MPC/AHHC connections.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * FICON CTC (AHHC/MPC/CTC) subchannel INOP after partner is    *
  * IPLed. For MPC/AHHC connections, the MPC group may become    *
  * active even though an individual READ or WRITE device fails  *
  * activation.                                                  *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Apply PTF                                                    *
  ****************************************************************
  Sample Configuration:
  
  HOST1===FICON MPC===HOST2
  
  The problem is summarized as follows:
  1) A FICON MPC connection configured with a single READ/WRITE
  subchannel pair is active between HOST1 and HOST2.
  2) HOST2 is IPLed while the FICON connection is active.
  3) HOST1 recognizes the outage and tries to recover the MPC
  subchannels.
  4) HOST1 times out while initiating X-side channel programs.
  5) The MPC subchannels hang in Contact/Wait state at this point.
  
  6) Later, HOST2 restarts the MPC connection.
  7) CCW traces on HOST1 show IOS receives two asynchronous Device
  Ends. VTAM treats the second async DE as if it were an ATTN.
  
  8) HOST1 initiates a XID0 processing upon receipt of the second
  async DE.
  9) A CCW trace on HOST1 showed that after y-side XID0 channel
  program was issued, it successfully completely with an interrupt
  with Channel End, Device End, followed immediately by an
  Attention interrupt.
  10) The VTAM internal trace revealed these were passed to VTAM
  in reverse order; attention routine (with ATTN), then Channel
  End routine with CE,DE.  The Attention routine (ISTTSCCA) did
  not properly remember that the ATTN had occurred, so no XID7
  channel program was started from HOST1.
  
  This resulted in HOST2 seeing the following message:
  
  IST574E START I/O TIMEOUT OCCURRED FOR xxxxxxxx
  
  While HOST1 issued the following messages:
  
  IST1222I xxxxx DEVICE xxxx IS INOPERATIVE, NAME IS xxxxxxxx
  IST467I CONTACTED ERROR TYPE 03 FOR ID = xxxxxxxx
  IST314I END
  

Problem conclusion

• ISTTSCXI - XSIDPEND has been updated to clear the XCNSASCB bit
  prior to driving the XID0 channel program.  This is done so the
  attention routine (ISTTSCCA) will correctly set NCBASYNC and
  XCNSAVATTN to drive the XID7 channel program.
  
  ISTTSC8E - Has been included for maintenance purposes.
  
  ISTXCNCB, ISTTSCCA and ISTRACCI - Have been updated to enhance
  the ATTN and INTX/INT2 trace entries for MPC interrupts.  These
  additional debug flags assisted in the resolution of this
  problem.
  
  The following z/OS Communications Server publications have been
  updated for this APAR:
  
  SNA Diagnosis Volume 2: FFST Dumps and the VIT
  
  Chapter: Appendix A
  
  
  ***************************************************************
  
  Heading: INTx Entry
  
  ***************************************************************
  
  Modify the existing INTx entry with the following
  
  information:
  
  1. Update the description of offset 08-17 as follows:
  
  
  Byte (hex)
  
  Contents
  
  08-17 First 16 bytes of transmit buffer, or 0, or
  device-dependent data
  
  
  ***************************************************************
  
  Heading: ATTx Entry
  
  ***************************************************************
  
  Modify the existing ATTx entry with the following
  
  information:
  
  1. Update the following field descriptions:
  
  
  Byte (hex)
  
  Contents
  
  06 CCW opcode or channel or flag byte (XCNFLAG2)
  
  07 0 or flag byte (XCNFLAG3)
  
  14 0 or flag byte (XCNFLAG) or for ATTT:
  
     * For the CDLC DLC: C
  
     * For the LCS DLC: L
  
     * For the CLAW DLC: W
  
     * For the CTC DLC: X
  
     * For the HYPERchannel DLC: H
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

  OA48265 UA78095 UA78096 OA48889

Modules/Macros

• ISTRACCI ISTTSC8E ISTTSCCA ISTTSCXI
  

Fix information

• Fixed component name

  VTAM V4 MVS/ESA

• Fixed component ID

  569511701

Applicable component levels

• R210 PSY UA78095

     UP15/08/26 P F508

• R220 PSY UA78096

     UP15/08/26 P F508

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.