*BSD News Article 18920


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Path: sserve!newshost.anu.edu.au!munnari.oz.au!foxhound.dsto.gov.au!fang.dsto.gov.au!myall.awadi.com.au!myall!blymn
From: blymn@awadi.com.au (Brett Lymn)
Newsgroups: comp.os.386bsd.bugs
Subject: Re: Problems with patchkit 0.2.4
Date: 29 Jul 1993 01:03:14 GMT
Organization: AWA Defence Industries Pty. Ltd.
Lines: 27
Message-ID: <BLYMN.93Jul29103314@siren.awadi.com.au>
References: <1993Jul15.070541.27917@cnplss5.cnps.philips.nl> <224in8$fl0@acsc.com>
	<CAAEBo.LFF@cyb.cojones.com> <1993Jul20.012738.2952@fcom.cc.utah.edu>
	<CAHvz0.38s@cyb.cojones.com> <BLYMN.93Jul25173659@siren.awadi.com.au>
	<231gm7INNrff@kralizec.zeta.org.au>
NNTP-Posting-Host: siren.awadi.com.au
In-reply-to: bde@kralizec.zeta.org.au's message of 27 Jul 1993 07:00:55 +1000

>>>>> On 27 Jul 1993 07:00:55 +1000, bde@kralizec.zeta.org.au (Bruce Evans) said:
Bruce> NNTP-Posting-Host: kralizec.zeta.org.au

Bruce> In <BLYMN.93Jul25173659@siren.awadi.com.au> blymn@awadi.com.au (Brett Lymn) writes:

>>>>>> On Wed, 21 Jul 1993 03:20:45 GMT, loodvrij@cyb.cojones.com (Bruce 'Loodvrij' Keeler) said:

>Bruce> OK, so I'll kill rts/cts for now, then?

>It would not hurt but then again if the flow control is not being
>used, why should it make any difference?

Bruce> The flow control lines may oscillate if they are not tied down.  This
Bruce> will cause a lot of unwanted modem status interrupts.  I've seen
Bruce> interrupt rates of 30K/sec on single port (10K/sec in, 10K/sec out,
Bruce> 10K/sec for flapping modem control lines).  The sio driver wants to
Bruce> have the modem status interrupt enabled almost all the time so as to
Bruce> be promptly informed about changes in carrier detect.

I have been misunderstood.  My statement was intended to mean that
leaving the rts/cts connected as the original poster had it would not
do any harm.  Most RS-232 interfaces I have worked with have the flow
control lines pulled to the correct levels with resistors... of course
on cheap & nasty pc hardware this is probably not the case.

--
Brett Lymn