On Tue, 2004-01-13 at 05:20, David Brownell wrote: > Neither; for now, disconnect() should wait until all the urbs complete. > Definitely no timeout.
I patched my driver to use asynchronous unlinking and to wait_for_completion() for the unlinked URB. There are two places now where I do that. First in my "wait_for_completion"-ioctrl call that detects the mentioned timeout of 3 seconds and then unlinks the URB. Second in my disconnect function. > Are you sure your wait_event() logic is working correctly? One > explanation for these questions is that it missed the event. Lets say, I am pretty sure. If it would merely miss the event and the URB would have successfully been unlinked the following unlink call would not return -EBUSY and there would not really be a problem (especially no kernel panic when I replug the device), wouldn't it? > I'd use URB_ASYNC_UNLINK myself, but that's unlikely to be the root > of the problem if your disconnect() is correctly waiting for all of > the urbs to complete. As said above my disconnect now waits asynchronously for the urb_completion but as I expected, it never comes to that: the first wait_event, resulting in the timeout, is now followed by an asynchronous unlink and then waits for the completion and never returns -> the program hangs. I still have these printks in giveback() and found to my surprise that this function gets called repeatedly for an other urb with a frequency of about 4/sec. This starts about the same time the unplugging is detected, that means shortly after I see the "uhci_hcd 0000:00:07.2: shutdown urb" and keeps on endlessly. At that time there is no usb device attached to the machine. Maybe this behavior is part of the problem or a hint where to search next? > Once the controller driver returned from its dequeue() > method, that meant the URB was going to be returned "soon". Isn't > there a uhci timer that's supposed to make that happen? I guess what I should do is to keep on trying to find the point where the URB "gets stuck" by distributing more printks to the right places. I know hcd_endpoint_disable()/unlink1() gets called and seems to do what it's supposed to but giveback_urb() is never called for this urb. Any suggestions where to go on? Thanks, Axel. ------------------------------------------------------- This SF.net email is sponsored by: Perforce Software. Perforce is the Fast Software Configuration Management System offering advanced branching capabilities and atomic changes on 50+ platforms. Free Eval! http://www.perforce.com/perforce/loadprog.html _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
