Re: [PATCH] USB: EHCI: fix for leaking isochronous data

[Soeren Moch]

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@xxxxxx>
> >
> > 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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