On Wed, 13 Dec 2006, Ethan Romander wrote: > On Tue, 2006-12-12 at 16:31 -0500, Alan Stern wrote: > > -snip- > > > > An observation: You are correct in guessing that there are fairly > > > frequent errors occurring on the keyboard's usb bus. The errors appear > > > similar to: > > > > > > ffff810139d06980 79568756 S Ii:006:01 -115 8 < > > > ffff810139d06980 84594648 C Ii:006:01 -110 0 > > > > > > in the usbmon trace. > > > > They seem to occur every 5 or 10 seconds, roughly. The most likely cause > > is a bad USB cable connection. You might want to check the cable, or > > even check if there's a cable inside the computer case running from the > > USB port to the motherboard. Try also connecting the keyboard to > > different USB ports on the computer. > > > > Is there anywhere to get a more informative description of the error > that is occurring? Is the mapping between error code and a specific > error message device specific?
The error codes are documented, in rather general form, in Documentation/usb/error-codes.txt. However I can tell you in this particular case what those -110 errors mean. They indicate that the computer did not receive a NAK packet from the keyboard in response to an IN packet. This could be because the keyboard never received the IN to begin with, or the keyboard received it but didn't send a NAK in response, or the keyboard did send the NAK but the computer didn't receive it. A USB bus analyzer could help to pin down exactly where the problem is, but they tend to be rather expensive. Alan Stern ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Linux-usb-users@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-users
