From: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Organization: tuxland
To: Luca Risolia <luca.risolia@studio.unibo.it>, Andrew Morton <akpm@osdl.org>
Subject: Re: [PATCH 10/33] usb: sn9c102_core free urb cleanup
Date: Tue, 14 Nov 2006 10:02:17 +0100
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Hello Luca,

> >- usb_free_urb() cleanup
> >
> >Signed-off-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
> >
> >--- linux-2.6.19-rc4-orig/drivers/media/video/sn9c102/sn9c102_core.c   
> > 2006-11-06 17:07:45.000000000 +0100 +++
> > linux-2.6.19-rc4/drivers/media/video/sn9c102/sn9c102_core.c 2006-11-06
> > 19:57:35.000000000 +0100 @@ -775,7 +775,7 @@ static int
> > sn9c102_start_transfer(struct
> >        return 0;
> >
> > free_urbs:
> >-       for (i = 0; (i < SN9C102_URBS) &&  cam->urb[i]; i++)
> >+       for (i = 0; i < SN9C102_URBS; i++)
> >                usb_free_urb(cam->urb[i]);
> >
> > free_buffers:
>
> This patch might cause usb_free_urb() to fail if not all the URBs have been
> allocated successfully: in this case, the original loop stops as soon as
> cam->urb[i] == NULL (where NULL is given from the failed allocation),
> while in the second loop there might be a not null cam->urb[i+n]
> pointing to an URB that has already been deallocated elsewhere.
>
> The same bug is present in PATCH 12/33.

Err ... you are right :/ In most drivers urb pointers get zeroed right after 
deallocation. Here they don't. So my patches might cause what you described.

Andrew can you please drop these two patches? 

usb-zc0301_core-free-urb-cleanup.patch
usb-sn9c102_core-free-urb-cleanup.patch

Thanks.

-- 
Regards,

	Mariusz Kozlowski
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