hint.uart.1 in device.hints causes freeze at boot

[Ian Smith]

On Fri, 26 Feb 2016 23:08:37 -0700, Warner Losh wrote:

(freebsd-current dropped; it'd only bounce)

 > Better still would be to split the current GENERIC.hints into two 
 > bits. One that was strictly for legacy (!ACPI and !PNPBIOS) 
 > situations, and one that we always load. There look to be at least a 
 > couple of hints that are universally relevant still. I might have a 
 > 200MHz pentium I can test this with...

Still need a few old dogs in the kennel to taste test new dogfood ..

 > As near as I can tell, only the following are relevant:
 > hint.fd.0.at="fdc0"
 > hint.fd.0.drive="0"
 > hint.fd.1.at="fdc0"
 > hint.fd.1.drive="1"
 > hint.acpi_throttle.0.disabled="1"
 > hint.p4tcc.0.disabled="1"
 >
 > and maybe
 >
 > hint.apm.0.disabled="1"
 > 
 > The floppy is for systems that have it, but won't add a floppy 
 > controller. APM hasn't been relevant since ~100MHz Pentium.

I still admin a 300MHz Celeron laptop (Compaq Armada 1500c, '98) happily 
using APM - ACPI powered off on removing AC power - but still running on
5.5-STABLE, with a recent uptime >1200 days .. don't tell anyone :)

 > The last two I'm unsure of.

Don't mess with those; it took Kevin Oberman years to get them there ..

acpi_throttle and p4tcc are generally evil; they don't save ANY power on 
top of est ono and hugely increase the number of steps (so, time) powerd 
has to churn through to adjust CPU speed to load, with minimum speeds as 
low as a sluggish 75-100MHz on some, so now best defaulting to disabled.

Certainly hard to find anything with a uart.1 in the last ~10 years, 
though I've no clue why or how that should cause a boot failure?

cheers, Ian