On Wed, 12 Jul 2006, Ajay Jain wrote: > Well, sometime back I was facing a problem when the windows came up > with a message on connecting this device of mine. The message was > "One of the usb devices attached to this computer has malfunctioned, and > Windows does not recognize it. For assistance in solving this problem, click > this message" > We did not have an acess to analyzer at that time, so we probed the > usb wire using LA, and we observed a reset. However we did not see > reset on the device end, which means that we did not get any reset > interrupt in our code. The problem was highly sporadic (one of the > most severe ones I have ever seen) and it occurred very very randomly. > Does anybody have any clues, so as to why this message appeared on the > host side? It is a very very generic message, and windows seems to > give this no matter the problem is with pre-enumeration or enumeration > stage.
I would guess that Windows displays this, as you say, whenever a USB device fails to complete enumeration. The message _has_ to be generic, because without access to the descriptors, Windows doesn't know anything about the device! > I was trying to extrapolate something from my current observation, may > be it is something quirky with the device. (As Alan pointed out, the > device is pulling up and pulling down). It is just a far-fetched guess > from my side. Maybe you can eliminate the host or the device by conducting a few simple tests. For instance, instead of connecting your device, just attach a pull-up resistor between D+ and Vbus and then see what the analyzer says. Or instead of using the Windows host, just attach a power source to Vbus and appropriate resistances between D+/gnd D-/gnd. If you still see the strange behavior with one side eliminated, then you will know the other side is responsible. 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
