multiple interface test case

Roman Kagan rkagan at
Tue Apr 12 06:40:45 EDT 2005

On Tue, Apr 12, 2005 at 11:26:06AM +0200, Duncan Sands wrote:
> > Weird that it hasn't bitten many other people yet.
> only a very few drivers do this kind of grab-a-bunch-of-other-devices
> stuff.

I would be surprized if the problem is triggered only if you grab a
_bunch_, and AFAICT there are quite a few drivers which grab at least
one via usb_driver_claim_interface and then release it via
usb_driver_release_interface, and thus should hit it too (unless there's
something like an off-by-one error which is triggered only when you grab
_all_ interfaces).

> All the locking has been changed in -mm by the way.  Anyway, what
> happens is that after the disconnect and everything, the driver has a
> reference count of 1, not 0.

I see.  So you just had rmmod hang, but not crash the system.  Sorry I
didn't get it at first.

But then I fail to see how usb_driver_release_interface on the currently
disconnect()-ed interface can be anything more than an noop.  Or do you
encounter the same problem when you exclude the current interface from
the list of released interfaces?


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