Re: [PATCH, RFC] usbmon: correct computing of the ISO packets withmmap

[Alan Stern]

On Sun, 14 Nov 2010, Pete Zaitcev wrote:

> On Mon, 15 Nov 2010 06:48:40 +0100
> Németh Márton <nm127@xxxxxxxxxxx> 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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