On Wed, 15 Feb 2006, Christian Iversen wrote:
> On Wednesday 15 February 2006 17:58, Alan Stern wrote:
> > This confirms that your hardware is physically broken; it's not a software
> > problem.
> >
> > There are three UHCI controllers, one per file above, each with two ports.
> > The port statuses are given in the lines marked "stat1" and "stat2". It
> > looks like your USB drive is plugged into port 1 of the third controller,
> > 0000:00:11.4, because that stat1 value is different from the others.
> >
> > The 9 in the 0490 indicates that the D+ signal line has a high voltage,
> > which never happens unless something is plugged in. However the 0 at the
> > end indicates that the controller thinks no device is connected.
> > Therefore the controller is not working correctly.
>
> That sounds like a trivial check that could save a lot of time debugging. How
> about something like the following pseudo-code? :
>
> if (data_plus_line_high(usb_dev) && nothing_plugged_in(usb_dev)) {
> printk("Fatal error: USB port on fire\n");
> }
Well, it's not quite so simple as the data values are dynamic. In
Jean-Philippe's case nothing was changing so the test was safe; in general
you would have to be very careful before drawing conclusions.
Alan Stern
-------------------------------------------------------
This SF.net email is sponsored by: Splunk Inc. Do you grep through log files
for problems? Stop! Download the new AJAX search engine that makes
searching your log files as easy as surfing the web. DOWNLOAD SPLUNK!
http://sel.as-us.falkag.net/sel?cmd=lnk&kid=103432&bid=230486&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
