RE: [Xen-devel] bug in usbback

["James Harper" <james.harper@xxxxxxxxxxxxxxxx>]

Also, a question on behaviour:

When we receive a reconfigure event, I assume that we should then read
'num-ports' and scan through each of the port-n values in xenstore. Is
there any guarantee that a device hasn't been unplugged and replugged
from the same port during the reconfiguration window? How should I
detect such a thing if the value of port-n hasn't changed? Should I then
probe each device? I'm doing this under Windows which is a bit more
picky and much less flexible...

Thanks

James

> -----Original Message-----
> From: Keir Fraser [mailto:keir.fraser@xxxxxxxxxxxxx]
> Sent: Saturday, 25 July 2009 20:13
> To: James Harper; xen-devel@xxxxxxxxxxxxxxxxxxx
> Cc: n_iwamatsu@xxxxxxxxxxxxxx
> Subject: Re: [Xen-devel] bug in usbback
> 
> Cc'ing the author...
> 
>  K.
> 
> On 25/07/2009 11:01, "James Harper" <james.harper@xxxxxxxxxxxxxxxx>
wrote:
> 
> > I think there is a bug in pvusb when the DomU does not respond to
the
> > XenbusStateReconfiguring state change and is then rebooted. This
caused
> > the following Dom0 (after a long freeze):
> >
> > BUG: soft lockup detected on CPU#0!
> >
> > Call Trace:
> >  <IRQ> [<ffffffff802a938c>] softlockup_tick+0xe1/0xef
> >  [<ffffffff80268f82>] timer_interrupt+0x408/0x466
> >  [<ffffffff8020fb41>] handle_IRQ_event+0x4d/0x95
> >  [<ffffffff802a9870>] __do_IRQ+0xb4/0x127
> >  [<ffffffff8026729c>] do_IRQ+0x44/0x4d
> >  [<ffffffff80375f6b>] evtchn_do_upcall+0x1b3/0x26e
> >  [<ffffffff8025c8d2>] do_hypervisor_callback+0x1e/0x2c
> >  <EOI> [<ffffffff88355b7e>] :usbbk:usbbk_schedule+0x1e0/0xa3f
> >  [<ffffffff8029482f>] autoremove_wake_function+0x0/0x2e
> >  [<ffffffff802947ba>] keventd_create_kthread+0x0/0x62
> >  [<ffffffff8835599e>] :usbbk:usbbk_schedule+0x0/0xa3f
> >  [<ffffffff802947ba>] keventd_create_kthread+0x0/0x62
> >  [<ffffffff802325e4>] kthread+0xd4/0x108
> >  [<ffffffff8025cb24>] child_rip+0xa/0x12
> >  [<ffffffff802947ba>] keventd_create_kthread+0x0/0x62
> >  [<ffffffff8025c827>] error_exit+0x0/0x71
> >  [<ffffffff80232510>] kthread+0x0/0x108
> >  [<ffffffff8025cb1a>] child_rip+0x0/0x12
> >
> > FYI, I am trying to get pvusb working under GPLPV and I had never
seen
> > the Reconfiguring/Reconfigured states before and so I wasn't doing
> > anything with them...
> >
> > James
> >
> >
> > _______________________________________________
> > Xen-devel mailing list
> > Xen-devel@xxxxxxxxxxxxxxxxxxx
> > http://lists.xensource.com/xen-devel
> 


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