netifd issue

[Felix Fietkau]

On 10.11.23 13:59, Felix Fietkau wrote:
> On 09.11.23 22:31, Hannu Nyman wrote:
>> e9hack kirjoitti 9.11.2023 klo 17.32:
>>> I face a strange behaviour since commit 
>>> 516ab774cc16d4b04b3b17a067cbf2649f1adaeb (system-linux: fix race condition 
>>> on bringing up wireless devices). After a reboot or a full restart of 
>>> hostapd via 'wifi down; sleep 30; killall hostapd; sleep 5; wifi', only the 
>>> first of 3 5G AP's is join to the configured bridge. The two faulty AP's 
>>> are up and connecting is possible, but there is no real network connection. 
>>> If I change one parameter of the faulty AP's in the config file and do a 
>>> 'wifi reload', than the 2 AP's are join to the bridges.
>>>
>>> ...
>>>
>>> If I change the sequence of the 5G AP's in the config file, the behaviour 
>>> after reboot doesn't change. Only phy1-ap0 does join to the bridge, either 
>>> to br-lan or to br-tor. The previous netifd commit 
>>> 40ed7363caf2b22b6e29ed9d9948189c2bc4c8f3 (device: fix build error on 32 bit 
>>> systems) doesn't have this issue.
>> 
>> 
>> I see the same error.
>> Some APs do not initially join the bridge, but after making a small pointless
>> edit to the AP's config in /etc/config/wireless and reloading wifi, the AP
>> then joins the bridge.
>> 
>> 
>>    OpenWrt SNAPSHOT, r24331-168beef1dd
>>    -----------------------------------------------------
>> root at router4:~# brctl show
>> bridge name     bridge id               STP enabled     interfaces
>> br-lan          7fff.c4411ef8a51f       no              lan4
>>                                                           lan2
>>                                                           hn5wpa3
>>                                                           lan3
>>                                                           lan1
>> root at router4:~# nano /etc/config/wireless
>> root at router4:~# wifi reload
>> root at router4:~# brctl show
>> bridge name     bridge id               STP enabled     interfaces
>> br-lan          7fff.c4411ef8a51f       no              lan4
>>                                                           hn5wpa2r
>>                                                           lan2
>>                                                           hn5wpa3
>>                                                           lan3
>>                                                           lan1
> 
> I think I found the cause of this regression while looking at the code
> again. It seems that the hotplug-added devices are removed too early
> based on DEV_EVENT_REMOVE events.
> Please try this fix: https://nbd.name/p/2791d8d4
Sorry, the last patch was incomplete. Here is the correct version:
https://nbd.name/p/8a6bc06b

Thanks,

- Felix