Re: [Linux-usb-users] USB: Non zero status
Alan Stern <[email protected]>
| Newsgroups | gmane.linux.usb.devel |
|---|---|
| Message-ID | <[email protected]> |
On Fri, 17 Aug 2007, Martin Bachem wrote: > yes, for me it does not matter if I use more URBs (I already use 2 per > endpoint), or if I use more packets per URB. The problem of too much > pending data which might produces a fifo overrun is the same than. I don't understand. Are you talking about TX URBs? How can you have too much pending data? What are the intervals of the Iso endpoints? It shouldn't be possible to send too much data for the device to handle. > many thanks for your explaination. The issue occures at ehci-hcd > currently. Too bad you didn't mention that earlier. > And if the error code -EXDEV could mean the ISO packets are > transmitted too late, than no Data could be lost at all, right? The > fifos should buffer that gap in the ISO stream... I'm not completely familiar with ehci-hcd, however -EXDEV means those packets were not transmitted at all. It doesn't mean they were transmitted too late. The fact that you are getting those errors may mean there's something wrong with ehci-hcd. A good thing to try would be to have your driver print out the value of urb->start_frame in the completion handler. Do it for all URBs, not just the ones with errors. Maybe something will stand out. Alan Stern ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel