kern/53340: Device probe for hard drive randomly fails after boot

[rnestor%tx.rr.com@localhost]

>Number:         53340
>Category:       kern
>Synopsis:       Device probe for hard drive randomly fails after boot
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Jun 04 14:05:00 +0000 2018
>Originator:     Robert Nestor
>Release:        NetBSD_8.0_RC1
>Organization:
>Environment:
NetBSD localhost 8.0_RC1 NetBSD 8.0_RC1 (GENERIC) #0: Tue May 22 17:51:55 UTC 2018  mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/amd64/compile/GENERIC amd64

>Description:
After installation on hard drive the newly installed system randomly fails to complete booting.  It fails during device enumeration where it can't always locate the hard disk that it is booting from.  This is using a BIOS boot on an HP 6200 MT where UEFI booting has been disabled.

The failure to find the hard drive happens about 50% of the time. 
>How-To-Repeat:
Reboot system
>Fix:
Unknown, but the workaround it to attempting to reboot the system.