From cstruble@quirk.com  Sat Jul  1 14:05:04 1995
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Date: Sat, 1 Jul 1995 17:04:56 -0400
From: cstruble@vt.edu
Reply-To: cstruble@vt.edu
To: FreeBSD-gnats-submit@freebsd.org
Subject: FreeBSD makes BIOS ignore serial ports (with fix)
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>Number:         576
>Category:       kern
>Synopsis:       BIOS doesn't recognize serial ports after FreeBSD use.
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          closed
>Quarter:
>Keywords:
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Sat Jul  1 14:10:01 1995
>Closed-Date:    Tue Aug 15 11:22:27 PDT 1995
>Last-Modified:  Tue Aug 15 11:24:17 PDT 1995
>Originator:     Craig Struble
>Release:        FreeBSD 2.0-BUILT-19950603 i386
>Organization:
Quirk Computing
>Environment:

	P60 Clone, with 16550A UARTS, Award BIOS 4.50

>Description:

	After FreeBSD uses the serial ports, the BIOS no longer recognizes them.

>How-To-Repeat:

	Use FreeBSD with a XFree86 and a serial mouse. The serial port the
	mouse is connected to is no longer recognized.

>Fix:
	
	In sio.c, comhardclose() from 2.0.5-RELEASE apply the following patch

*** sio.c.orig  Tue May 30 04:03:06 1995
--- sio.c       Sat Jul  1 16:29:44 1995
***************
*** 985,990 ****
--- 985,995 ----
        if (!(com->state & CS_DTR_OFF)
            && !(unit == comconsole && (COMCONSOLE || boothowto & RB_SERIAL)))
                kdc_sio[unit].kdc_state = DC_IDLE;
+       /*
+        * Turn off fifos, make the BIOS happy
+        */
+       outb(iobase + com_fifo, 0);
+ 
        splx(s);
  }


>Release-Note:
>Audit-Trail:
State-Changed-From-To: open->closed 
State-Changed-By: bde 
State-Changed-When: Tue Aug 15 11:22:27 PDT 1995 
State-Changed-Why:  
Fixed in rev. 1.110 of /sys/i386/isa/sio.c 
>Unformatted:


