pankaj chauhan wrote: > dave, > > Thanks alot for useful information. > > Is there any way in which i can verify that is it the > fault of device (i.e device is trying to draw more > current) or my host controller is faulty (as you > mentioned that some Host controllers behave in such > way)? > >
lsusb -v | grep -i power will show you the numbers that usb-core is working with. If youve got another linux box, and/or another hub, try some cross-testing, see if you can isolate it. > Thanks > PC > --- David Brownell <[EMAIL PROTECTED]> wrote: > > >>> i am using 2.6.11, >>> >> Try to use a more current kernel. Likely it won't >> matter >> here, but 2.6.11 is over 18 months old by now ... :) >> >> >> >>> and EHCI HCD. during boot up i get >>> following message: >>> >>> "usb 1-0:1.0: over-current change on port 1" >>> >>> and after the system is up none of the USB device >>> connected to USB port are detected. >>> >>> can you please tell me what over-current change >>> >> mean. >> >> USB devices can draw a certain amount of current, >> with >> a maximum of 500 mA in high power configurations. >> >> USB hubs, like root hubs, may be able to detect when >> that current limit is exceeded; if so, it's reported >> as an "over current" error. >> >> >> >>> and Is this error responsible for my device not >>> getting detected. >>> >> Likely. When a port issues an overcurrent fault, >> the device connected to it is disconnected. >> >> >> We have seen cases where some USB controllers (EHCI >> and >> UHCI, I don't recall it with OHCI) *wrongly* report >> such >> over-current errors ... at least, "wrongly" in the >> sense >> that no device is connected, so we think the >> motherboard >> must be at fault, badly wired or whatever. >> >> - Dave >> >> ------------------------------------------------------------------------- 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-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
