On Thu, Jul 22, 2021 at 7:44 PM Loic Poulain loic.poulain@linaro.org wrote:
On Thu, 22 Jul 2021 at 18:14, Sergey Ryazanov ryazanov.s.a@gmail.com wrote:
On Thu, Jul 22, 2021 at 6:39 PM Loic Poulain loic.poulain@linaro.org wrote:
By default there is no rtnetlink event generated when registering a netdev with rtnl_link_ops until its rtnl_link_state is switched to initialized (RTNL_LINK_INITIALIZED). This causes issues with user tools like NetworkManager which relies on such event to manage links.
Fix that by setting link to initialized (via rtnl_configure_link).
Shouldn't the __rtnl_newlink() function call rtnl_configure_link() just after the newlink() callback invocation? Or I missed something?
Ah right, but the first call of rtnl_configure_link() (uninitialized) does not cause RTM_NEWLINK event (cf __dev_notify_flags). It however seems to work for other link types (e,g, rmnet), so probably something to clarify here.
Just check additional netdev creation with hwsim:
# ip link add wwan0.3 parentdev wwan0 type wwan linkid 3
On the other console:
# ip -d mon 6: wwan0.3: <POINTOPOINT,NOARP> mtu 1500 qdisc noop state DOWN group default link/none promiscuity 0 minmtu 68 maxmtu 65535 wwan numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535
But I saw no notification at the moment of wwan_hwsim module loading. This happens since I missed the rtnl_configure_link() call in the wwan_create_default_link() after the default link successful creation :(
So we need your fix at least in the default link creation routine to fix ca374290aaad ("wwan: core: support default netdev creation"). Something like this:
diff --git a/drivers/net/wwan/wwan_core.c b/drivers/net/wwan/wwan_core.c index 3e16c318e705..374aa2cc884c 100644 --- a/drivers/net/wwan/wwan_core.c +++ b/drivers/net/wwan/wwan_core.c @@ -984,6 +984,8 @@ static void wwan_create_default_link(struct wwan_device *wwandev, goto unlock; }
+ rtnl_configure_link(dev, NULL); /* trigger the RTM_NEWLINK event */ + unlock: rtnl_unlock();
-- Sergey