Messages in this thread | | | Date | Mon, 15 Nov 2010 10:06:50 -0500 (EST) | From | Alan Stern <> | Subject | Re: [PATCH, RFC] usbmon: correct computing of the ISO packets with mmap |
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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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