On Thu, 9 Sep 2004, Dominique Larchey wrote: > Dear Sir, > > I have written a linux 2.6 driver for an USB ADSL > modem. This modem is a two way ATM cell transmitter > that has one endpoint for incomming cells and > another endpoint for outgoing cells. > > For incomming data, I use two BULK URBs to wait for > data. On completion, I queue data and schedule > a tasklet to process it. Then I get free buffers > and resubmit the completed URB. > > I encounter the following problem I did not expect: > > The driver work well but after a few hours > (which are unpredictable), it seems that > the two URBs that wait for incomming data > are stalled forever (I log the submission > time jiffies to check that). > > One could think that the modem is in fault > (ie it stops sending data) but simply unlinking > the URBs and resubmitting them unlocks the > incomming channel. Them after some time > (hours) it might lock again. > > I wonder if this could be a behavior of the > uhci-hcd driver ? Is it possible that > URB become stalled forever even when incomming > data is pending ?
Certainly it's possible. It's not supposed to happen, but it might. > Thanks a lot in advance for any answer > or redirection to another developer. > > Dominique Larchey > LORIA, CNRS If you want to get more information, you should turn on the USB debugging option in your kernel configuration. When you load the uhci-hcd module, add the parameter "debug=4" to the modprobe command line. Then the next time you see the communication stall, copy the contents of /proc/driver/uhci/* (whichever file in that directory corresponds to the controller used by your modem). Post the file contents, and also post your system log. Maybe something in there will explain what you're seeing. Alan Stern ------------------------------------------------------- This SF.Net email is sponsored by: YOU BE THE JUDGE. Be one of 170 Project Admins to receive an Apple iPod Mini FREE for your judgement on who ports your project to Linux PPC the best. Sponsored by IBM. Deadline: Sept. 13. Go here: http://sf.net/ppc_contest.php _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
