On Mon, 25 Jul 2005, Andrew Morton wrote: > Begin forwarded message: > > Date: Tue, 19 Jul 2005 18:24:25 +0200 > From: DervishD <[EMAIL PROTECTED]> > To: Linux-kernel <[email protected]> > Subject: USB debouncing? > > > Hi all :) > > I have a new MP3 player, and when I disconnect it from the USB > port, my logs says: > > <30>Jul 19 18:11:05 kernel: usb.c: USB disconnect on device 00:07.3-1 > address 2 > <27>Jul 19 18:11:06 kernel: hub.c: connect-debounce failed, port 1 > disabled > > What is that 'connect-debounce' for? Is the port damaged? Am I > doing anything wrong? > > Thanks a lot in advance :) > > Raúl Núñez de Arenas Coronado
>From the form of the log message, it looks like you're using Linux 2.4 or an early version of 2.6. You could try booting 2.6.12 instead; most likely the message will disappear. The "connect-debounce" is used whenever a device connects or disconnects. The idea is that as the plug is inserted and removed, for a brief period of time the electrical surfaces make and break contact repeatedly (this is called "bouncing"). So that the system doesn't get confused by all the on-and-off status messages this would cause, the driver waits until everything has been stable for a hundred milliseconds or so. But it doesn't wait very long, and if the contacts are still bouncing then that error message appears. It doesn't necessarily mean the port is damaged, or that the plug is. It might indicate that you're being too slow when you remove the plug. Or it might simply be misleading -- the current driver has a longer debouncing period than earlier versions did, which could be enough to eliminate the errors. Alan Stern ------------------------------------------------------- SF.Net email is sponsored by: Discover Easy Linux Migration Strategies from IBM. Find simple to follow Roadmaps, straightforward articles, informative Webcasts and more! Get everything you need to get up to speed, fast. http://ads.osdn.com/?ad_id=7477&alloc_id=16492&op=click _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
