On Thu, Jan 15, 2015 at 06:25:22PM +0200, Pantelis Antoniou wrote: > Hi Greg, > > > On Jan 14, 2015, at 22:41 , Greg Kroah-Hartman <[email protected]> > > wrote: > > > > On Wed, Jan 14, 2015 at 07:24:22PM +0200, Pantelis Antoniou wrote: > >> I’ll try to dig around tomorrow and see what the real device reference > >> counts > >> are, but my hunch goes like this: > >> > >> MUX > >> +—- ADAPTER > >> +— DEV. > >> > >> Mux remove method is called, i2c_del_mux_adapter is called on all the > >> channels > >> of the mux, calling in turn i2c_del_adapter which hangs on completion of > >> the > >> dev_released. > >> > >> The call to device_unregister never calls the device_type callback > >> (i2c_adapter_dev_release) > >> because the reference count is not 1 at that point, someone else is having > >> another > >> reference. > > > > First of all, my head hurts. Tracking device references ain’t easy. Is there > some kind > of debugging method you’d recommend for this?
You can turn on debugging for kobjects and the driver core if you want to slow down your system log a bunch, but it can be helpful for trickier issues. Or just sprinkle a few printks around. > > I don't remember the i2c core code at all, that was a long time ago. > > > > Bummer. Do you remember code you wrote 12 year ago and haven't looked at for at least 11? Why expect others to as well? :) thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
