Oliver Neukum <oliver@xxxxxxxxxx> writes: > Am Samstag, 23. Juni 2012, 17:32:09 schrieb Bjørn Mork: >> Ming Lei <tom.leiming@xxxxxxxxx> writes: >> > On Sat, Jun 23, 2012 at 4:45 PM, Bjørn Mork <bjorn@xxxxxxx> wrote: > >> > Suppose there will be another usbnet driver which has its own subdriver >> > too, the same trick of checking need to be added again if not taking the >> > general way of simply removing 'usb_set_intfdata(intf, NULL);' in >> > usbnet_disconnect. >> >> Yes, I guess so. >> >> I am just worrying (maybe too much) about the unknown consequences of >> removing that code in usbnet, not fully understanding why it was there >> in the first place. And I do not want to take the blame and cleanup >> work if anything goes wrong :-) Fixing it in qmi_wwan feels much safer. > > void usbnet_cdc_unbind(struct usbnet *dev, struct usb_interface *intf) > { > struct cdc_state *info = (void *) &dev->data; > struct usb_driver *driver = driver_of(intf); > > /* disconnect master --> disconnect slave */ > if (intf == info->control && info->data) { > /* ensure immediate exit from usbnet_disconnect */ > usb_set_intfdata(info->data, NULL); > usb_driver_release_interface(driver, info->data); > info->data = NULL; > > 1. We mirror the minidrivers closely, which reduces errors > 2. unbind() is called with the data anyway and after disconnect() > the intfdata is not valid anyway, because the interface may have been > reprobed. Sorry, I did not understand what you meant we should do here. The extra usb_set_intfdata(, NULL) in usbnet_disconnect() won't make any difference for that piece of code, will it? And the USB core ensures that intfdata is set to NULL before any reprobing, so that will never be a problem. That's the reason why it seems redundant setting it in usbnet_disconnect(). Bjørn -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html