Re: kern/50182: Crash + core possibly related to USB KVM switching or g910 keyboard

[David Holland <dholland-bugs%netbsd.org@localhost>]

The following reply was made to PR kern/50182; it has been noted by GNATS.

From: David Holland <dholland-bugs%netbsd.org@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: 
Subject: Re: kern/50182: Crash + core possibly related to USB KVM switching
 or g910 keyboard
Date: Sun, 6 Sep 2015 00:24:33 +0000

 On Fri, Aug 28, 2015 at 05:35:00AM +0000, swiftgriggs%gmail.com@localhost wrote:
  > I switch back and forth with my startech 2-port DVI + USB KVM
  > switch. Once I've switched "away" and then "back" I often lose
  > control of the system (though video stick around sometimes -
  > frozen). Once I reboot I get a core in /var/crash. I thought you
  > folks might want to take a look.
  > 
  > Let me know how to send the core files. 
 
 Sending the crash dumps is expensive (they're large) and probably not
 worthwhile. Instead, the best bet is probably for you to run gdb on
 one and tell us what comes up.
 
 The method for doing that is as follows (if anyone seeing this mail
 wants to expand/clarify/correct please do):
 
  - first, uncompress the core file as gdb can't read them while
 compressed:
 	# cd /var/crash
 	# gunzip netbsd.6.core.gz   (or whichever one seems good)
 
 If you don't have space for it in /var/crash you can copy/move it
 somewhere else.
 
  - run gdb on /netbsd if it's the same kernel that crashed (I have
 found lately that the copy saved in /var/crash by savecore doesn't
 work, so if you've rebuilt the kernel or anything since you got the
 core speak up)
 	# gdb /netbsd
 
  - load the core and get a stack trace
 	(gdb) target kvm netbsd.6.core
 	   :
 	(gdb) backtrace
 
 Send us what gdb prints.
 
 This is the first step -- there may be other useful information
 available, but that will depend on what this turns up.
 
  > Switch with a Startech KVM using a Logitech G910 keyboard (a
  > strange expensive beast of a keyboard with many unrecognized
  > keycodes for special keys)
 
 It will probably also be helpful to send in the parts of dmesg.boot
 that pertain to this; or if you aren't sure, all of dmesg.boot.
 
 -- 
 David A. Holland
 dholland%netbsd.org@localhost