On a newer kernel, only the first port of a bridge is brought up

[Klaus Kudielka]

 > I tried to run OpenWrt with a bleeding-edge net-next kernel (commit
> 0e804326759d), then noticed that only the first port of a bridge is
> brought up automatically, the rest are down and not members of the
> bridge.

> i.e. with the following settings
> network. at device  <https://lists.openwrt.org/mailman/listinfo/openwrt-devel>[0]=device
 > network. at device  <https://lists.openwrt.org/mailman/listinfo/openwrt-devel>[0].ports='lan1' 'lan2' 'lan3' 'lan4'
 > network. at device  <https://lists.openwrt.org/mailman/listinfo/openwrt-devel>[0].type='bridge'
 > network. at device  <https://lists.openwrt.org/mailman/listinfo/openwrt-devel>[0].name='br-lan'

> Only lan1 is in br-lan, and I have to manually configure the rest:

Exactly the same happens to me on Turris Omnia with master, either 5.4 
OpenWrt kernel or 5.10 OpenWrt kernel.

I bisected this to "2801fe6132c4e2e364e2d5a304594185351b501b netifd: 
update to the latest version".

And, I believe, Petr has noticed the same thing with 21.02.

Regards, Klaus