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Date:      Mon, 13 Oct 1997 01:10:12 -0700 (PDT)
From:      Doug White <dwhite@gdi.uoregon.edu>
To:        Eduardo Viruena Silva <mrspock@esfm.ipn.mx>
Cc:        freebsd-questions@FreeBSD.ORG
Subject:   Re: Serial Ports' IRQ and ports.
Message-ID:  <Pine.BSF.3.96.971013010855.9609I-100000@gdi.uoregon.edu>
In-Reply-To: <Pine.BSF.3.96.971012145501.4878B-100000@michelle.esfm.ipn.mx>

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On Sun, 12 Oct 1997, Eduardo Viruena Silva wrote:

> Serial Ports are configurated according to the following table:
> 
> 	FreeBSD	MS-DOS	io-address  MS-DOS's IRQ
> 	sio0	com1	0x3f8 		4
> 	sio1	com2	0x2f8		3
> 	sio2	com3	0x3e8		4
> 	sio3	com4	0x2e8		3
> 
> But using the same IRQ for ports 0 & 2  or 2 & 3 causes kernel
> configuration utility displays:   "CONF" warning.
> 
> Can the interrupt service routines distinguish which port is requiring
> attention if I give the configuration in the table to the serial ports ?

No.  FreeBSD requires that every device have a unique IRQ, with exceptions
made for multiport I/O cards and parallel ports in polled mode. 

> Do I have to specify a different IRQ level for each port ?

Yes.

Doug White                              | University of Oregon  
Internet:  dwhite@resnet.uoregon.edu    | Residence Networking Assistant
http://gladstone.uoregon.edu/~dwhite    | Computer Science Major





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