[Qemu-devel] commit da57febfed "qdev: give all devices a canonical path" broke usb_del

[Michael Tokarev <mjt@tls.msk.ru>]

While dealing with USB issues today I noticed that
usb_del monitor command is broken, attempting to
delete any usb device immediately results in assertion
failure:

(qemu) usb_del 0.1
ERROR:qom/object.c:408:object_delete: assertion failed: (obj->ref == 0)
Aborted


I bisected this issue to commit:

commit da57febfed7bad11be79f047b59719c38abd0712
Author: Paolo Bonzini <pbonzini@redhat.com>
Date:   Tue Mar 27 18:38:47 2012 +0200

    qdev: give all devices a canonical path

    A strong limitation of QOM right now is that unconverted ports
    (e.g. all...) do not give a canonical path to devices that are
    part of the board.  This in turn makes it impossible to replace
    PROP_PTR with a QOM link for example.

    Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
    Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
    Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>


The problem is still present in current qemu/master git.

I'm not sure what to do with this.

See also http://lists.gnu.org/archive/html/qemu-devel/2012-07/msg00199.html --
Peter Maydell reoprted this very issue a while back but no one replied.

Thanks,

/mjt