kern/59248: 4.9-RELEASE, ACPI Panic with Dell Latitude D600

[Andre Grosse Bley]

John Baldwin <jhb at FreeBSD.org> said the following on freebsd-hackers:

> Ah, the problem is that ACPI tries to sleep from a task, which is not safe
> to do.  This is not easy to fix. :(

Actually, it may not be too hard.  In current, ACPI uses its own thread
to run the tasks in, so stable would need the same sort of thing.
Basically, ACPI needs to start up a kproc and needs to have its own
taskqueue again that uses this kproc for its execution context.