On Sat, 2018-08-25 at 09:43 +0200, Jiri Slaby wrote: > On 08/24/2018, 06:38 PM, Ben Hutchings wrote: > > On Fri, 2018-07-20 at 14:13 +0200, Greg Kroah-Hartman wrote: > > > 4.4-stable review patch. If anyone has any objections, please let me know. > > > > > > ------------------ > > > > > > From: Jiri Slaby <jslaby@xxxxxxx> > > > > > > [ Upstream commit 0ee1f4734967af8321ecebaf9c74221ace34f2d5 ] > > > > [...] > > > --- a/drivers/net/usb/r8152.c > > > +++ b/drivers/net/usb/r8152.c > > > @@ -3139,7 +3139,8 @@ static int rtl8152_close(struct net_devi > > > #ifdef CONFIG_PM_SLEEP > > > unregister_pm_notifier(&tp->pm_notifier); > > > #endif > > > - napi_disable(&tp->napi); > > > + if (!test_bit(RTL8152_UNPLUG, &tp->flags)) > > > + napi_disable(&tp->napi); > > > clear_bit(WORK_ENABLE, &tp->flags); > > > usb_kill_urb(tp->intr_urb); > > > cancel_delayed_work_sync(&tp->schedule); > > > > This flag appears to be set only if the USB device is actually > > disconnected. In case the driver is unbound for some other reason > > (like the module is removed), the same problem will occur. > > Could you elaborate? I thought this would happen: > module_exit -> usb_deregister -> usb_unbind_device -> rtl8152_disconnect > -> unregister_netdev -> rtl8152_close > > Am I missing something? What I mean is that if the USB device has not been *physically* disconnected then its usb_device::state will not be USB_STATE_NOTATTACHED. So rtl8152_disconnect() will not set the RTL8152_UNPLUG flag and rtl8152_close() will still call napi_disable() which will hang. Some options to fix this: - Add a separate flag which rtl8152_close() checks and rtl8152_disconnect() always sets - Call dev_close() before netif_napi_del() Ben. -- Ben Hutchings, Software Developer Codethink Ltd https://www.codethink.co.uk/ Dale House, 35 Dale Street Manchester, M1 2HF, United Kingdom
