Panic with usb serial

M. Warner Losh imp at
Tue Apr 1 17:59:08 UTC 2008

In message: <20080329.191710.1169638035.imp at>
            "M. Warner Losh" <imp at> writes:
: In message: <20080329222049.GA80263 at>
:             Jeremy Chadwick <koitsu at> writes:
: : On Sat, Mar 29, 2008 at 10:11:04PM +0000, Vince wrote:
: : > 	Is it expected that removing a usb serial adapter while you have a 
: : > connection (eg tip) using it will panic a -stable system? I know it is 
: : > expected if you remove a mounted umass device so wanted to see if its known 
: : > behavior for serial before I file a pr. (adapter is <FTDI usb serial 
: : > converter, class 0/0, rev 1.10/4.00, addr 3>)
: : > -stable version as of the 25th march, (may have existed before but the 
: : > first time I forgot to close tip before removing the device was on this 
: : > version.)
: : 
: : I would expect that the problem is identical in the sense that with a
: : connection established, you have an open file descriptor which is
: : associated with a serial device that uses USB.
: : 
: : So, yes, I would expect this behaviour based on the track record.
: : Should it happen?  The answer is no.  File a PR?
: : 
: : Also, I'd like to know what USB serial adapter you're using (brand,
: : model, and a website of it if possible), for unrelated reasons.  Thanks!
: That's odd, because I use an FTDI based serial device all the time for
: hacking on embedded systems.  The problem that I have is 100% CPU
: usage on a tip process until I kill it.

Actually, the reason for this is that I fixed a bug that gave me
panics...  During the review process, it was pointed out that others
had better changes.  These have been included in -current, but I don't
think have been merged back to RELENG_7 yet.  They aren't in 7.0.


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