On Mon, 3 Jul 2006, Foli Ayivoh wrote: > Hi Alan, > > I doubt that the keyboard or the cable is the cause, because it works very > well under a > different OS (not to mention here). No problems, no hassle.
Maybe some change to the host controller driver has caused these errors, although I don't see how. What normally happens is that the computer asks the keyboard every few milliseconds if any keystrokes have occurred, and most of the time the keyboard says "No". But in your logs, every 50-80 milliseconds the computer doesn't get any answer from the keyboard at all. That's an error, and after 10 errors the computer resets the keyboard. But the errors still occur after the reset... Typically this "lack of an answer" is caused by a hardware communications problem. The fact is, you don't have any easy way to tell whether this sort of problem is present or not. For instance, the log definitely shows that it _is_ present with 2.6.16, even though the keyboard seems to work okay. For all we know, the same problem could be present with XP too. Go look at your usbmon file for 2.6.16. The vast majority of the log consists of repeated lines looking like this: f77627c0 1709870136 S Ii:003:01 -115 8 < f711ef60 1709871132 C Ii:003:02 -110 0 f711ef60 1709871136 S Ii:003:02 -115 3 < f77627c0 1709926122 C Ii:003:01 -110 0 Each of those -110 values is a timeout error, meaning that no response was received from the keyboard. The corresponding -115 value is the computer retrying the request. In the example above, the error occurred 56 milliseconds after the request was submitted. > Could it be some timing and/or latency problem? > > (??or preemption or HZ values??)(although no changes made in kernel config > between > Kernel 2.6.16 and Kernel 2.6.17, oldconfig used) I don't think so. But since I don't know the real cause, it's impossible to be certain. Remember, the problem was _not_ caused by some change between 2.6.16 and 2.6.17, because it was already present in 2.6.16. > This is my actual "hardware config", although it might look strange, but it > "works" well > under the other OS and under Linux (2.6.16) too: > > ________________ _________________________ > | | | | > | USB STORAGE |----------|USB INPUT ONE |----------------------- > | | | | | > ---------------- | SEVEN PORT USB HUB | | > | | | > ------------------------- | > (WITH EXTERNAL POWER) | > FOR TESTING ONLY | > - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -|- > - > EVERY DAY USAGE | > | > ________________ _________ | > | | | | | > | KEYBOARD ONE |---------------------------------------------|USB | | > | | | | | > ---------------- | HOST | | > | ONE | | > _________________________ | | | > | | | USB|---- > | OUTPUT ONE|----------|USB | > | | | | > | | --------- > | USB/DVI/AUDIO | > | KVMP-SWITCH | LINUX > | | 2.6.16 OK > | | WINXP OK > ________________ | | ---------- > | | | OUTPUT TWO| LINUX > | KEYBOARD TWO |----------|USB | 2.6.17 NOK > | | | | > ---------------- | | > | | > _________ | | > | | | | > | MOUSE |----------|USB | > | | | OUTPUT THREE| > --------- | | > | | > | | > | | > | | > | | _________ > | | | | > | OUTPUT FOUR|----------|USB | > | | | | > ------------------------- | HOST | > (WITH EXTERNAL POWER) | TWO | > | | > | | > | | > | | > --------- > > LINUX ONLY > 2.6.16 OK > > The affected keyboard is "KEYBOARD TWO" that is connected via the KVM-SWITCH. Does the keyboard work better if you attach it directly to one of the computers, bypassing the KVM switch? Perhaps the switch causes those communications errors. Also, can you post the output from "lsusb -v"? Alan Stern Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
