On Sun, 10 Aug 2014, Florian Fainelli wrote: > Le 10/08/2014 20:23, Dexuan Cui a écrit : > >> -----Original Message----- > >> From: Greg KH [mailto:gregkh@xxxxxxxxxxxxxxxxxxx] > >>>>> > >>>>> IMO the most feasible and need-the-least-change solution may be: > >>>>> the hyperv network VSC driver passes the event > >>>>> RNDIS_STATUS_NETWORK_CHANGE to the udev daemon? > >>>>> > >>>> No, don't do that, again, act like any other network device, drop the > >>>> link and bring it up when it comes back. > >>>> > >>> Hi Greg, > >>> Do you mean tearing down the net device and re-creating it (by > >>> register_netdev() and unregister_netdev)? > >> > >> No, don't you have link-detect for your network device? Toggle that, I > >> thought patches to do this were posted a while ago... > >> > >> But if you really want to tear the whole network device down and then > >> back up again, sure, that would also work. > > Hi Greg, Stephen, > > > > Thanks for the comments! > > > > I suppose you meant the below logic: > > if (refresh) { > > rtnl_lock(); > > netif_carrier_off(net); > > netif_carrier_on(net); > > rtnl_unlock(); > > } > > > > We have discussed this in the previous mails of this thread itself: > > e.g., http://marc.info/?l=linux-driver-devel&m=140593811715975&w=2 > > > > Unluckily this logic doesn't work because the user-space daemons > > like ifplugd, usually don't renew the DHCP immediately as long as they > > receive a link-down message: they usually wait for some seconds and if > > they find the link becomes up soon, they won't trigger renew operations. > > (I guess this behavior can be somewhat reasonable: maybe the daemons > > try to not trigger DHCP renew on temporary link instability) > > Is that such a big deal? If you know you spend much of your time in > ifplugd, why not use something different that triggers a DHCP renewal > faster, or fix ifplugd? In the case of ifplugd, it has parameters -u | --delay-up= which defaults to 0 seconds, and -d | --delay-down= which defaults to 5 seconds. Maybe for hyperv you could specify --delay-down=0. I don't know if other daemons such as systemd have similar options. It might still be good to have some modest delay between the netif_carrier_off(net) and netif_carrier_on(net). -Bill _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
