kern/53184: system panics on shutdown

[venture37%geeklan.co.uk@localhost]

>Number:         53184
>Category:       kern
>Synopsis:       system panics on shutdown
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Apr 15 13:15:00 +0000 2018
>Originator:     Sevan Janiyan
>Release:        NetBSD 8.99.14
>Organization:
>Environment:
i386 build
>Description:
Issuing a halt or reboot command results in the system panicking.

show panic reports
Panic string: cpu_switchto: switching above IPL_SCHED (8)

bt
breakpoint()
vpanic()
snprintf()
cpu_switchto()
sleepq_block()
turnstile_block()
mutex_vector_enter()
acpiec_lock()
acpiec_space_handler()
AcpiEvAddressSpaceDispatch()
AcpiExAccessRegion()
AcpiExFieldDatumIo()
AcpiExWriteUpdateRule()
AcpiExInsertIntoField()
AcpiExWriteDataToField()
AcpiExStoreObjectToNode()
AcpiExStore()
AcpiExOpcode_1A_1T_1R()
AcpiDsExecEndOp()
AcpiPsParseLoop()
AcpiPsParseAml()
AcpiPsExecuteMethod()
AcpiNsEvaluate()
AcpiEvaluateObject()
AcpiEnterSleepStatePrep()
acpi_enter_sleep_state()
cpu_reboot()
sys_reboot()
syscall()
>How-To-Repeat:
issue halt or reboot.

>Fix: