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    SubjectRe: [PATCH] USB: EHCI: fix for leaking isochronous data
    On 21.03.2013 20:10, Arnd Bergmann wrote:
    > On Thursday 21 March 2013, Jason Cooper wrote:
    >> On Thu, Mar 21, 2013 at 06:04:59PM +0100, Soeren Moch wrote:
    >
    >>>
    >>> Now I found out what is going on here:
    >>>
    >>> In itd_urb_transaction() we allocate 9 iTDs for each URB with
    >>> number_of_packets == 64 in my case. The iTDs are added to
    >>> sched->td_list. For a frame-aligned scheduling we need 8 iTDs, the
    >>> 9th one is released back to the front of the streams free_list in
    >>> iso_sched_free(). This iTD was cleared after allocation and has a
    >>> frame number of 0 now. So for each allocation when now_frame == 0 we
    >>> allocate from the dma_pool, not from the free_list. The attached
    >>> patch invalidates the frame number in each iTD before it is sent to
    >>> the scheduler. This fixes the problem without the need to iterate
    >>> over a iTD list.
    >>>
    >>> Signed-off-by: Soeren Moch <smoch@web.de>
    >>
    >> Wow! Great work Soeren! Talk about a long road to a small fix. Thanks
    >> for keeping after it.
    >
    > +1
    >
    > I hardly understand half of the description above, but that much sounds
    > plausible. Is this a bug fix that should get backported to stable kernels?
    >
    > Arnd
    >
    I think this patch should go to stable kernels, too. But I'm not an
    expert here...

    Soeren


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