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| author | Peter Holik <peter@holik.at> | 2011-03-18 18:47:44 +0100 |
|---|---|---|
| committer | Paul Gortmaker <paul.gortmaker@windriver.com> | 2011-06-26 12:47:13 -0400 |
| commit | 6ebf5728b9a9ca9f3a7f2ef1aad42ac850785aec (patch) | |
| tree | 953be3e7a3eb7f945d1f5e177c632cd578a0cfd6 | |
| parent | ff0e076b0421ba7b8dba647300c99fd24e823550 (diff) | |
| download | linux-rt-6ebf5728b9a9ca9f3a7f2ef1aad42ac850785aec.tar.gz | |
USB: uss720 fixup refcount position
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>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
| -rw-r--r-- | drivers/usb/misc/uss720.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/drivers/usb/misc/uss720.c b/drivers/usb/misc/uss720.c index 4ff21587ab03..9727daa1cc72 100644 --- a/drivers/usb/misc/uss720.c +++ b/drivers/usb/misc/uss720.c @@ -177,12 +177,11 @@ static struct uss720_async_request *submit_async_request(struct parport_uss720_p 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; } |