kern/63621: [usb] USB MemoryStick Reader stalls/crashes system

Herve Quiroz herve.quiroz at
Tue Dec 7 17:50:30 PST 2004

The following reply was made to PR kern/63621; it has been noted by GNATS.

From: Herve Quiroz <herve.quiroz at>
To: Dmitry Morozovsky <marck at>
Cc: freebsd-gnats-submit at
Subject: Re: kern/63621: [usb] USB MemoryStick Reader stalls/crashes system
Date: Wed, 8 Dec 2004 02:49:34 +0100

 On Tue, Nov 30, 2004 at 03:12:58PM +0300, Dmitry Morozovsky wrote:
 > - 5.3-R: data transfers stall; however, msdosfs survives `umount -f' and 
 > remounting.
 I've been experimenting with 5.3-RELEASE and 5.3-STABLE myself. The USB
 drive will work in most of the cases without the need of the trick I
 mentioned earlier. I can boot the system, plug the drive, mount, and
 'svn update' and everything will go fine. Same regarding rsync or 'cp
 Anyway, as I said, this will work in "most of the cases". Indeed, on 5.3
 I am experiencing a new problem: sometimes, when I plug my drive, the
 system freezes. No panic, no trace in the logs (I have not enabled any
 debug or verbose mode though -- tell me if you require such trace). The
 system just hangs. Then there must be something eating the CPU as my fan
 will shortly after that start to increase its speed automatically.
 The very bad here is that I cannot predict when this problem will arise.
 The drive may have been successfuly plugged/unplugged several times
 since last reboot and then fail at the next plugging. And this time, I
 am not allowed to save any work in progress nor try to sync my buffers
 before the panic.
 Needless to say, I tested it with different USB drive models and it
 still (sometimes) hangs, although I haven't performed further tests to
 determine precisely how often... I even replaced my RAM chips to be sure
 (but we're almost sure there's no cause here as the problem arise on
 several boxes at my office and home).
 This issue being IMHO even worse than the former one (given I have no
 workaround -- other than to pray each time I plug the drive), I think I
 will try and avoid using my USB drive as much as possible. Still, I am
 willing to help you sort this out by testing any patch you think would
 be worth.
 Hum, now that I think of it, the freeze seems to occur when I plug the
 drive and my ATA disk is stressed. Last time it happened (one hour ago)
 was during a 'cvs update -PdT' from my local ports repository. Could be
 just another coincidence though...

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