kern/79420: panic using uplcom or uftdi serial adaptor and modem (USB)

[Mike Tancsa]

The following reply was made to PR kern/79420; it has been noted by GNATS.

From: Mike Tancsa <mike at sentex.net>
To: freebsd-gnats-submit at FreeBSD.org
Cc:  
Subject: Re: kern/79420: panic using uplcom or uftdi serial adaptor and
  modem (USB)
Date: Sun, 03 Apr 2005 11:45:04 -0400

 Ian Dowse provided the patch below which seems to stop the panics.  At 
 least 24hrs of testing has not resulted in a panic yet.
 
 --------------------------------------------
 
 In this case I wonder if the transfer needs to be aborted at all,
 since it is just restarted immediately afterwards. Mike, maybe you
 could try the following patch? Sorry, I haven't tested this, so I
 may be missing something obvious.
 
 Ian
 
 Index: dev/usb/ucom.c
 ===================================================================
 RCS file: /dump/FreeBSD-CVS/src/sys/dev/usb/ucom.c,v
 retrieving revision 1.51.2.2
 diff -u -r1.51.2.2 ucom.c
 --- dev/usb/ucom.c	30 Jan 2005 01:00:10 -0000	1.51.2.2
 +++ dev/usb/ucom.c	2 Apr 2005 13:10:27 -0000
 @@ -929,11 +929,13 @@
 
   	DPRINTF(("ucomstop: %d\n", flag));
 
 +#if 0
   	if (flag & FREAD) {
   		DPRINTF(("ucomstop: read\n"));
   		ucomstopread(sc);
   		ucomstartread(sc);
   	}
 +#endif
 
   	if (flag & FWRITE) {
   		DPRINTF(("ucomstop: write\n"));