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From: Michael Smith <msmith@atrad.adelaide.edu.au>
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Subject: Re: locking up
To: terry@lambert.org (Terry Lambert)
Date: Fri, 16 Aug 1996 11:55:03 +0930 (CST)
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        joerg_wunsch@uriah.heep.sax.de, freebsd-hackers@FreeBSD.ORG,
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In-Reply-To: <199608160156.SAA01893@phaeton.artisoft.com> from "Terry Lambert" at Aug 15, 96 06:56:43 pm
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Terry Lambert stands accused of saying:
> 
> > > Yet I still get random lockups.  :-(
> > 
> > LED state is updated at every VC switch, even if the LEDs are all off.
> > 
> > The biggest problem with automating a recovery from the hung state is that
> > it's almost impossible for the keyboard driver to tell the difference
> > between a hung keyboard and a user off making a coffee.
> > 
> > None of the reset methods that I know of are safe enough to run on a 
> > regular basis - you'd have too many people complaining about losing 
> > keystrokes.  I guess you could have a 'no LEDs' option for syscons 
> > for people who lock up too regularly...
> 
> Yet, DOS does it.

DOS doesn't VC switch.  The keyboard code I've worked on (at the keyboard
end), _specifically_ hangs around after a key that it thinks will generate
a LED update has been pressed, waiting for the update so that it doesn't
collide.

(Mind you, this code also snooped for collisions and generally did a fairly
good job of avoiding them).

> 					Terry Lambert

-- 
]] Mike Smith, Software Engineer        msmith@atrad.adelaide.edu.au    [[
]] Genesis Software                     genesis@atrad.adelaide.edu.au   [[
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