usbconfig reset ugen4.2 hanging since an hour

[Alexander Best]

On Tue Nov  2 10, Alexander Leidinger wrote:
> Quoting Alexander Motin <mav at FreeBSD.org> (from Tue, 02 Nov 2010  
> 14:02:17 +0200):
> 
> >Alexander Leidinger wrote:
> >>
> >>Quoting Hans Petter Selasky <hselasky at freebsd.org> (from Tue, 2 Nov 2010
> >>10:36:41 +0100):
> 
> >>>If you dump all threads in this state I think you will see that USB is
> >>>waiting
> >>
> >># procstat -kk 29213
> >>  PID    TID COMM             TDNAME           KSTACK
> >>29213 100291 usbconfig        -                mi_switch+0x188
> >>sleepq_switch+0x13c sleepq_timedwait+0x40 _sleep+0x320 pause+0x30
> >>usb_pause_mtx+0x94 usb_ioctl+0x171 devfs_ioctl_f+0x73 kern_ioctl+0x9d
> >>ioctl+0xc5 syscallenter+0x1af syscall+0x34 Xint0x80_syscall+0x21
> >>
> >>>somewhere in umass_detach(), which is preventing the usbconfig reset from
> >>
> >>No umass_detach in there...
> >
> >umass_detach() (if there) should be in some other thread.
> 
> Not here:
> ---snip---
> # procstat -kka | grep umass_detach
> 
> ---snip---
> 
> >>>grabbing the SX-lock associated with serialisation. Because
> >>>umass_detach() is
> >>>not returning we are stuck.
> >>
> >>And there is no way to use some kind of timeout for cases which cause
> >>problem reports (like umass_detach() and maybe this one)? I could
> >>imagine several possibilities: usbconfig tries a trylock first (maybe
> >>several times) and if it does not succeed in a specified timeperiode, it
> >>returns an error. Adidtionally there is maybe the possibility to
> >>determine if a command did not finish in a given timeperiode and print
> >>out a warning message (syslog) to have an indication, that somthing is
> >>not in a good condition.
> >
> >Not sure what should it give. We should track the real problem, not the
> >consequences. Possible reason could be that due to some error umass/CAM
> >leaked some references, which made impossible to destroy CAM bus on
> >stick disconnection. But to diagnose it we need much more info.
> 
> Something I could provide? Some kdb magic I could copy&paste?

i believe you're experiencing the same i issue i have [1].

cheers.
alex

[1] http://www.mail-archive.com/freebsd-usb@freebsd.org/msg07599.html

> 
> Bye,
> Alexander.
> 
> -- 
> Phosflink, v.:
> 	To flick a bulb on and off when it burns out (as if, somehow,
> 	that will bring it back to life).
> 		-- Rich Hall & Friends, "Sniglets"
> 
> http://www.Leidinger.net    Alexander @ Leidinger.net: PGP ID = B0063FE7
> http://www.FreeBSD.org       netchild @ FreeBSD.org  : PGP ID = 72077137

-- 
a13x