Re: [git pull] Input update for 2.6.17

[Greg KH <greg@kroah.com>]

On Mon, Jun 26, 2006 at 11:13:19PM -0700, Linus Torvalds wrote:
> 
> 
> On Mon, 26 Jun 2006, Dmitry Torokhov wrote:
> > 
> > Please pull from:
> > 
> > ????????git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input.git
> 
> I think this (or USB) may have problems.
> 
> I get a spinlock debugging fault with the current kernel on one of my 
> machines at bootup, with the trace-back being:
> 
>   Process: khubd
> 	spin_bug
> 	_raw_spin_lock
> 	_spin_lock
> 	__mutex_lock_slowpath
> 	mutex_lock
> 	input_unregister_device
> 	hidinput_disconnect
> 	hid_disconnect
> 	usb_unbind_interface
> 	__device_release
> 	device_release_driver
> 	bus_remove_device
> 	device_del
> 	usb_disable_device
> 	usb_disconnect
> 	hub_thread
> 	kthread
> 
> it happens pretty early after bootup, but I don't know what triggers that 
> usb disconnect (it may be the hand-over from UHCI->EHCI. Greg? Does that 
> make sense?)

Yes, if you have the UHCI driver loaded first, then when EHCI is loaded,
it disconnects everything on the bus and re-enumerates it.

But EHCI is built into the kernel first, before UHCI, so unless you are
using modules, nothing should be getting disconnected at boot time.

I really doubt you are using modules, so I don't know why it would be
disconnected.  What does the kernel log show right before this happened?
Any chance to enable CONFIG_USB_DEBUG?

thanks,

greg k-h