[c-nsp] 6800 ISSU issue

[Chuck Church]

All,

       Ran into an issue with using FSU on a quad-sup 6800 VSS pair with
Sup6T.  We're going from 15.3(1)SY2 to 15.5(1)SY2.  It appears after the
standby sup upgrade starts (after the issu loadversion command is done), a
3 minute timer is expiring and causing an automatic abort.  From the logs:

Apr 21 2019 05:52:34.856: %ISSU_PROCESS-SW1-6-LOADVERSION_INFO: Standby-ICS
has gone offline, wait for reboot

Apr 21 2019 05:55:34.866: %ISSU_PROCESS-SW1-3-ABORT: Starting abort
sequence, reason: LOADVERSION: Standby-ICS has not come back online

Now we could see via the console cable that the standby would eventually
boot up.  Due to the version changes there was an FPGA upgrade done and I
believe a second boot of it.  Thus more than the 3 minute timer I'm
hitting.  Anyone seen this before and/or know what to do?

Thanks,

Chuck