IZ90962: DEAD LOCK / CRASH IN USB WATCHDOG HANDLER WITH CDROM BACKUP APPLIES TO AIX 5300-10

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• When using USB cdrom and backing up with heavy IO and
  if SCSI errors are occurring a crash may occur with
  the following scsi errors and stack trace:
  
  Oct 15 04:08:27 SYSDUMP    U DUMP_STATS
  Oct 15 04:06:59 minidump   U MINIDUMP_LOG
  Oct 15 04:06:59 ABEND      P KERNEL_ABEND
  Oct 15 04:09:44 errdemon   T ERRLOG_ON
  Oct 14 03:32:07 cd0        T DISK_ERR4
  Oct 14 03:15:46 cd0        T DISK_ERR4
  Oct 12 05:09:30 cd0        P DISK_ERR1
  Oct 12 05:08:57 cd0        P DISK_ERR1
  Oct 12 05:08:22 cd0        P DISK_ERR1
  
  pvthread+01CB00 STACK:
  [0001BF00]abend_trap+000000 ()
  [0052BF04]slock+000524 (??, ??)
  [000090C4].disable_lock+0000C0 ()
  [04E08C64]watchdog_hndlr+000064 (??)
  [0007D6E8]watchdog+000388 ()
  [000A1594]sys_timer+000154 (??)
  [000A2274]clock+000334 (??
  

Local fix

Problem summary

• When using USB cdrom and backing up with heavy IO and
  if SCSI errors are occurring a crash may occur with
  the following scsi errors and stack trace:
  
  Oct 15 04:08:27 SYSDUMP    U DUMP_STATS
  Oct 15 04:06:59 minidump   U MINIDUMP_LOG
  Oct 15 04:06:59 ABEND      P KERNEL_ABEND
  Oct 15 04:09:44 errdemon   T ERRLOG_ON
  Oct 14 03:32:07 cd0        T DISK_ERR4
  Oct 14 03:15:46 cd0        T DISK_ERR4
  Oct 12 05:09:30 cd0        P DISK_ERR1
  Oct 12 05:08:57 cd0        P DISK_ERR1
  Oct 12 05:08:22 cd0        P DISK_ERR1
  
  pvthread+01CB00 STACK:
   0001BF00 abend_trap+000000 ()
   0052BF04 slock+000524 (??, ??)
   000090C4 .disable_lock+0000C0 ()
   04E08C64 watchdog_hndlr+000064 (??)
   0007D6E8 watchdog+000388 ()
   000A1594 sys_timer+000154 (??)
   000A2274 clock+000334 (??
  

Problem conclusion

• Schedule the watchdog handler as a offlevel handler
  

Temporary fix

Comments

• 5300-10 - use AIX APAR IZ90962
  5300-11 - use AIX APAR IZ90775
  5300-12 - use AIX APAR IZ90834
  6100-06 - use AIX APAR IZ89476
  7100-00 - use AIX APAR IZ89893
  

APAR Information

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

  IZ87679

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

Fix information

• Fixed component name

  AIX 5.3

• Fixed component ID

  5765G0300

Applicable component levels

• R530 PSY U840552

     UP11/02/23 I 1000

PTF to Fileset Mapping

• U840552 devices.usbif.08025002.rte 5.3.10.4