Date: Thu, 25 May 2006 14:43:43 -0700 From: othermark <atkin901@yahoo.com> To: freebsd-stable@freebsd.org Subject: Re: Odd RS232 problem Message-ID: <e558eg$3c1$1@sea.gmane.org> References: <200605131413.17020.doconnor@gsoft.com.au> <20060513123030.GA32024@intserv.int1.b.intern> <200605231923.21263.doconnor@gsoft.com.au> <6.2.3.4.0.20060523095411.11c41c00@64.7.153.2>
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Mike Tancsa wrote: > At 05:53 AM 23/05/2006, Daniel O'Connor wrote: >>On Saturday 13 May 2006 22:00, Holger Kipp wrote: >> >> > If you encounter silo overflows, you might need to increase >> > cp4ticks in sio.c, eg >> > - cp4ticks = speed / 10 / hz * 4; >> > + cp4ticks = speed / 10 / hz * 40; >> > and/or you might want to change hz from 1000 back to 100. >> >>OK, I'll try it. > > This fixes the overflows for me as well. I have a number of boxes out > in the field running with this local modification (40 vs 4). Without > it, I have problems running a PCI modem at speeds better than 9600 > without causing overflows. Yes, I had a laptop that exhibited this same problem and this change did fix it. I believe this is described in the following PR: http://www.freebsd.org/cgi/query-pr.cgi?pr=kern/51982 I had tried to work on this patch to provide a bounded sysctl for the multiplier, that way you could just set the hint on boot up in order to fix this problem. With a little trial and error you could find the lowest tick value that works for the interrupt load. One of these days I'll get back to figuring out all the places I need to add code to get that hint to work correctly. -- othermark atkin901 at nospam dot yahoo dot com (!wired)?(coffee++):(wired);
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