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SubjectRe: [PATCH, RFC] usbmon: correct computing of the ISO packets with mmap
On Sun, 14 Nov 2010, Pete Zaitcev wrote:

> On Mon, 15 Nov 2010 06:48:40 +0100
> Németh Márton <nm127@freemail.hu> wrote:
>
> > ev_type == 'S' && usb_urb_dir_out(urb) ---> data is available, we'll need it
>
> The write submission case should be covered by the transfer_buffer_length,
> I think. Is there a driver that only sets the ISO descriptors but not
> the overall length?

If there is, it's a bug. usb_submit_urb() could check for that sort of
thing -- although so far nobody has complained of problems, so checking
doesn't seem necessary.

Other things usb_submit_urb() could check for, but currently doesn't,
include:

Make sure the packet offsets are non-decreasing;

Make sure the packet don't overlap in the buffer;

Make sure the spacing between two consecutive packets
in the buffer doesn't exceed some upper limit (needed
by ehci-hcd).

Alan Stern

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