umass panic (after detaching/attaching card-reader 3 times)
Matthew Dillon
dillon at apollo.backplane.com
Wed Mar 17 11:32:55 PST 2004
:
:I would love to, if I could find hardware that reproduces the problem. I
:went shopping for USB thumb drives a while back and only came up with
:working ones.
:
:I have a Soyo KT400 Dragon Lite machine at home.
:
:--
:Doug White | FreeBSD: The Power to Serve
:dwhite at gumbysoft.com | www.FreeBSD.org
It took me a while to reproduce the panic from the first bug report
that was posted to our list, but I was finally able to do it by
plugging in three or four USB mass storage devices all at once,
in various combinations before and after booting. The key in reproducing
the bug is to get the system to detach a UMASS during the boot sequence,
that's what causes the (now disconnected) CAM bus rescan timeout to blow
up. For some unknown reason the UMASS/USB subsystem will often attach/
deattach/reattach devices during boot, even though you haven't unplugged
them. I don't know why... it still happens in DFly but it no longer
crashes.
I have brought the DFly ISO image up to date and added a README.USB
section and also an ehci.ko module (the rest of USB is already compiled
into GENERIC), which should be enough for anyone having this problem
to play around with the USB subsystem from a DragonFly ISO CD boot
without having to touch their hard drive. The ISO is available here
(around 70MB gzip'd, 200MB unzipped). It's a fully live boot CD, just
login as root. You can even edit things in /etc, /tmp, /dev, etc...
they are MFS mounts, of course.
ftp://ftp.dragonflybsd.org/iso-images/dfly-20040317b.iso.gz
I am curious if the people reporting the problem on FBsd-4 still have
the problem when the above DFly ISO. If not then I would say that
pretty much guarentees that my recent bug fixes (described in my previous
posting to this list) have dealt with the issue. If so then I have more
work to do and would appreciate a bug report / dmesg output / backtrace
from DDB if possible :-)
p.s. the ISO fits on those cute mini CD-R's.
-Matt
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