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    Subject[16/23] USB: uss720 fixup refcount position
    From: Peter Holik <peter@holik.at>

    commit adaa3c6342b249548ea830fe8e02aa5b45be8688 upstream.

    My testprog do a lot of bitbang - after hours i got following warning and my machine lockups:
    WARNING: at /build/buildd/linux-2.6.38/lib/kref.c:34
    After debugging uss720 driver i discovered that the completion callback was called before
    usb_submit_urb returns. The callback frees the request structure that is krefed on return by
    usb_submit_urb.

    Signed-off-by: Peter Holik <peter@holik.at>
    Acked-by: Thomas Sailer <t.sailer@alumni.ethz.ch>
    Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

    ---
    drivers/usb/misc/uss720.c | 7 +++----
    1 file changed, 3 insertions(+), 4 deletions(-)

    --- a/drivers/usb/misc/uss720.c
    +++ b/drivers/usb/misc/uss720.c
    @@ -176,12 +176,11 @@ static struct uss720_async_request *subm
    spin_lock_irqsave(&priv->asynclock, flags);
    list_add_tail(&rq->asynclist, &priv->asynclist);
    spin_unlock_irqrestore(&priv->asynclock, flags);
    + kref_get(&rq->ref_count);
    ret = usb_submit_urb(rq->urb, mem_flags);
    - if (!ret) {
    - kref_get(&rq->ref_count);
    + if (!ret)
    return rq;
    - }
    - kref_put(&rq->ref_count, destroy_async);
    + destroy_async(&rq->ref_count);
    err("submit_async_request submit_urb failed with %d", ret);
    return NULL;
    }



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