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Received: by minnie.vk1xwt.ampr.org with NNTP id AA6891 ; Fri, 15 Jan 93 10:38:27 EST Path: sserve!manuel.anu.edu.au!munnari.oz.au!sgiblab!spool.mu.edu!uunet!mcsun!sun4nl!tuegate.tue.nl!svin09!wzv!gvr.win.tue.nl!guido From: guido@gvr.win.tue.nl (Guido van Rooij) Newsgroups: comp.unix.bsd Subject: Re: [386bsd] Need help with multiport driver Keywords: com-multiport Message-ID: <4358@wzv.win.tue.nl> Date: 16 Jan 93 14:21:08 GMT References: <1j4ghmINNqv@homer.telco-nac.com> Sender: news@wzv.win.tue.nl Lines: 38 dave@telco-nac.com (David Cornejo) writes: >Has anyone using cgd's com-multiport driver used it with a Kouwell >KW-531A? When I compile my kernel with COM_MULTIPORT defined >cu/tip'ing to these ports causes a hang. If I comment out the top two >ports and compile without COM_MULTIPORT the two remaining ports work >fine. My board is configured for the default DOS configuration, i.e. >two ports are at the standard COM1 & COM2 addresses and interrupts >and the other two are at non-standard I/O addresses (I forget them >right now) and share INT 3. The documentation with the driver mentions >this board, but gives no details. >Any help or suggestions would be most appreciated. >(BTW Despite my ineptitude in setting up the config, my serial ports >work much nicer, thanks Chris!) In the multiport driver, interrupts per uart are disabled. Chris told me that this was according to the spe of multiport boards. However if you just share some single ports, you should not disable them. Note that if the cards are according to ibm's original serial port, you can put two separate boards on the same irq. If they are not, you might gte into problems, unless you change your hardware a bit. (make sure the int output of the uart is connected to the irq output of the baird with an open collector). A better solution would be to change the boards irq from 3 or 4 to, say 5 (parallel 2) if you don't use that one. (also for this you have to change the hardware, but its fairly trivial to do). This might be hard if you dont have that many free interrupts. So you'll have to choose between the 2. What I told above is true in general for separate boards sharing the same irq. Of course you can always try if it works okay when sharing interrupts, though I wouldn't know of it can break your uarts. To enable interrupts again on shared irq's, just look at the MULTIPORT define, and you'll see the 2 spots where they are disabled. (one in attach() and one in ioctl() -Guido