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Date: Thu, 11 Apr 2002 17:00:49 +1000 (EST)
From: Bruce Evans <bde@zeta.org.au>
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To: Jake Burkholder <jake@locore.ca>
Cc: John Baldwin <jhb@FreeBSD.org>, <cvs-all@FreeBSD.org>,
	<cvs-committers@FreeBSD.org>, Brian Somers <brian@FreeBSD.org>
Subject: Re: cvs commit: src/sys/dev/digi digi.c
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On Wed, 10 Apr 2002, Jake Burkholder wrote:

> Apparently, On Wed, Apr 10, 2002 at 09:06:18AM -0400,
> 	John Baldwin said words to the effect of;
> > I've thought about having some sort of separate API for code that just ways to
> > delay.  Right now they use tsleep() on a channel that never gets woken up with
> > a timeout.  If we had a delay(int timo) function then it could use a callout
> > when callouts were working and fall back to DELAY() in the cold case.
>
> No, this is wrong.  Anything that uses cold is wrong.  The correct fix is to
> move the clock initialization earlier in boot to be before the device probe.

This can't be done in a machine independent way.  Clock interrupts
might be shared, and then enabling them first would cause either endless
interrupts if another device is driving the interrupt.  This happens
not to be a problem on i386's because clock interrupts aren't shared.

I think this is still a problem for configuration of drivers with shared
non-clock interrupts.  The handling of this seems to have regressed in
-current on i386's.  RELENG_4 at least has large comments about it.

Bruce


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