On Fri, 23 Apr 2010, Eric W. Biederman wrote:

quoted text
> >> This might also be one of the false positives I reworked the code in
> >> 2.6.34 to fix, by putting different attributes in different sysfs
> >> classes but it doesn't look like it.
> >
> > Are you sure?  It kind of looks like it to me.  Maybe the fix wasn't 
> > present in the kernel Dave was running.
> 
> Given your description this does look like a false positive.  
> 
> Rereading the code it looks like my error was not in reading into
> usb_disable_device and realizing that the children of the disabled
> device would be removed.
> 
> I think we will still have a false positive in 2.6.34 if one the
> children also has an instance of the bConfigurationValue attribute.  As
> all attributes are made to live in the same lockdep class.

That can certainly happen.  In fact, you can test it yourself easily 
enough if you have a USB device.  Just plug it in and do:

	echo 0 >/sys/bus/usb/devices/usbN/bConfigurationValue

where N is the number of the USB bus your device is attached to.

Alan Stern

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