On Sun, 10 Jun 2007, Oliver Neukum wrote:

> Am Sonntag, 10. Juni 2007 schrieb Greg KH:
> > > Yes, it could be done that way, I think.  It'll take more work than a 
> > > simple search-and-replace.  The trickiest part is how to unlink an URB 
> > > after it has been submitted but before it has been handed to the HCD...
> > 
> > We allow that today?  How, multiple threads doing the submit and then
> > unlink call?  That's looney.  We should not worry about that until after
> 
> Isn't that exactly what a resubmission in the completion handler is?

No.  It may be similar in some vague sense but it's not the same thing 
at all.  What Greg and I are talking about is this:

        CPU 0                           CPU 1
        -----                           -----
        call usb_submit_urb
                                        call usb_unlink_urb
          call hcd->driver->urb_enqueue

What you're talking about is this:

        CPU 0
        -----
        call usb_hcd_giveback_urb
          call urb->complete
            call usb_submit_urb

It doesn't involve multiple threads or unlinking.

Alan Stern


-------------------------------------------------------------------------
This SF.net email is sponsored by DB2 Express
Download DB2 Express C - the FREE version of DB2 express and take
control of your XML. No limits. Just data. Click to get it now.
http://sourceforge.net/powerbar/db2/
_______________________________________________
linux-usb-devel@lists.sourceforge.net
To unsubscribe, use the last form field at:
https://lists.sourceforge.net/lists/listinfo/linux-usb-devel

Reply via email to