On Tue, Jun 29, 2010 at 04:37:09PM +0800, Manjunath Doddavenkatappa wrote: > > Dear all, > > We have a sensor device with a USB connector (device's name > is TelosB in case if your aware of it). We use USB active cables to > connect such devices to a Linux PC (2.6.22-14-generic). Length of > these active cables range from 5 to 25 meters. Problem is while long > 25 meter active cables are used for connection. Communication with a > device connected via such a long cable is fine most of the time, but > connection would go down at least once/twice a day (although the > corresponding /dev/ttyUSBX is visible). Each time the connection is > lost, removal and insertion of the USB kernel module "ehci-hcd" will > make the connection alright again (modprobe -vr ehci-hcd; modprobe > -v ehci-hcd). > > Is there any way to fix this without having to remove and insert the > module every time. I am new to USB framework on Linux. Can you unplug the cable and plug it back and it will work? Can you provide the full kernel logs for when the problem happens? I've never seen anything good about "active cables" that are that long, I would really not recommend ever using such a thing. thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
