It is valid for all releases (but I could be wrong).
However, notice that I did not say that there are not issues on the 2.4GHz band; I said that there are not issues on the 2.4GHz band related to the channel used: either it works for all channels, or it does not work for any channel.
On the 5GHz band, DFS causes lots of issues, depending on the channel used.
I know for a fact that, with low ack disabled (which might or might not matter), I have very reproducible issues with channel 1 on my solar panels Wi-Fi adapter and issues on channel 11 with my Harmony Hubs.
This is only with 21.02 versions and no issue at all on 19.07 versions. So there definitely is an issue which is related to channels.
I do not have time to check it out with low ack enabled, but will have time this weekend to try it with low ack enabled. Not holding my breath, but it might be the reason of my issues.
SQM QoS. I'm also going to try Software flow offloading enabled. Not sure if that'll help performance as well.
Software flow offloading isn't going to work with SQM, it's one or the other. I use SQM because it works great maxing out my 500/35 Mbit cable modem while having A+ bufferbloat / A+ quality results.
For some reason I thought that was concerning HWO not necessarily SWO. Definitely want my SQM though.
Exactly, thats why I have fixed Channels for both 2.4GHz (11) and 5GHz (36) because ever since using the Linksys WRT1900ACS I had Radar Detection Issues on the 5GHz wifi with I think specially with width 80MHz and performance losses when streaming over Wifi, as described here cant-connect-to-5ghz-after-radar-is-detected-on-wrt1900acs or here 5ghz-radio-disappears-after-a-while-fritzbox-4040 for example (I was probably trying to use fixed channels in the DFS range back then). Interesting fact, can't remember ever having had those problems on my old OpenWrt 19.07 on a FritzBox 4040 though. But thats another story I guess.
My current wifi config
config wifi-device 'radio0'
option type 'mac80211'
option channel '36'
option hwmode '11a'
option path 'soc/soc:pcie/pci0000:00/0000:00:01.0/0000:01:00.0'
option htmode 'VHT80'
option cell_density '0'
option country 'FR'
config wifi-iface 'default_radio0'
option device 'radio0'
option mode 'ap'
option macaddr '00:11:22:33:44:55'
option ssid 'MY_SSID_5'
option encryption 'psk2'
option key 'VERY_SECURE'
option network 'WIFI'
config wifi-device 'radio1'
option type 'mac80211'
option channel '11'
option hwmode '11g'
option path 'soc/soc:pcie/pci0000:00/0000:00:02.0/0000:02:00.0'
option cell_density '0'
option country 'FR'
option htmode 'HT40'
config wifi-iface 'default_radio1'
option device 'radio1'
option mode 'ap'
option macaddr '00:11:22:33:44:66'
option ssid 'MY_SSID'
option encryption 'psk2'
option key 'VERY_SECURE'
option network 'WIFI'
Still running smooth 
mostly on 5GHz (Can tell because I have min. 4h+ MS Teams calls a day 
)
Running OpenWrt SNAPSHOT, r18470-cb85aea869 on WRT1900AC v2 for a half of month and bumped into the issue, that 5GHz wireless stops working and in logs I see:
Fri Jan 28 19:55:44 2022 daemon.notice hostapd: wlan0: AP-STA-DISCONNECTED 80:xx:xx:xx:xx:8f
Fri Jan 28 19:55:44 2022 daemon.info hostapd: wlan0: STA 80:xx:xx:xx:xx:8f IEEE 802.11: disassociated due to inactivity
Fri Jan 28 19:56:04 2022 kern.err kernel: [117756.083092] ieee80211 phy0: cmd 0x9122=UpdateEncryption timed out
Fri Jan 28 19:56:04 2022 kern.err kernel: [117756.089773] ieee80211 phy0: return code: 0x1122
Fri Jan 28 19:56:04 2022 kern.err kernel: [117756.094488] ieee80211 phy0: timeout: 0x1122
Fri Jan 28 19:56:04 2022 kern.err kernel: [117756.098955] wlan0: failed to remove key (0, 80:xx:xx:xx:xx:8f) from hardware (-5)
Fri Jan 28 19:56:04 2022 daemon.info hostapd: wlan0: STA 80:xx:xx:xx:xx:8f IEEE 802.11: deauthenticated due to inactivity (timer DEAUTH/REMOVE)
Fri Jan 28 19:56:04 2022 kern.debug kernel: [117756.181183] ieee80211 phy0: MACREG_REG_INT_CODE: 0x0000
Fri Jan 28 19:56:24 2022 kern.err kernel: [117776.090220] ieee80211 phy0: cmd 0x9111=SetNewStation timed out
Fri Jan 28 19:56:24 2022 kern.err kernel: [117776.096217] ieee80211 phy0: return code: 0x1111
Not all devices connected to 5GHz are affected at the beginning.
kmod-mwlwifi - 5.10.89+2020-02-06-a2fd00bb-2
mwlwifi-firmware-88w8864 - 2020-02-06-a2fd00bb-2
This is good information. Thank you for sharing.
What log settings do I need to see those extra details? Is a special debug build required?
Previous Timeout-related issues on mwlwifi firmware often showed up after newer kernels and a few times were remedied by increasing:
#define MAX_WAIT_FW_COMPLETE_ITERATIONS 10000
Link: https://github.com/kaloz/mwlwifi/blob/111118dc2ea3b592a5f7dff18c82d57a651970e7/hif/pcie/pcie.c#L36
At one point in time that was set to 2000 milliseconds. Even after the Marvell developer increased it to 10000 milliseconds, he had suggested that it could still be increased further if necessary due to mwlwifi using mutex.
It might be interesting if someone could try testing this by compiling in driver with this set to 15000 milliseconds or even 20000 milliseconds.
I don’t have a build environment, but I would be happy to test it if someone compiles to matching 21.02.1 matching kernel driver.
I can generally reproduce the 5 GHz radio crashing approx. every 3 days on average.
You are welcome
No, just logread command provides this logs.
It's been about a week here. The snapshot I installed helped a lot. Network cutouts went from multiple times per hour to maybe one every few days. Still not ideal... but it is better.
Look careful, when set encryption. 802.11w should be set to disabled.
WPA2/WPA3 mixed mode does not work on MacOS with 802.11w disabled - keeps asking about password
Other people have said that WPA3 doesn't work on these routers in OpenWRT. It's a separate problem from the stability issues being tested here. See here for more discussion from a year ago: WPA3 support (maybe?) on Linksys WRT series router
any news regarding 21.02.2 release?
P.S. because I am thinking about downgrading to 19.07
Why not just run a snapshot? Have a 60 day uptime on my WRT32X with a snapshot from late Dec, it's been great. Yes it would be nice to see .2 released soon, but I think all the devs are focused on the move to nftables.
I have 2 issues running snapshot:
phy0: cmd 0x9122=UpdateEncryption timed out
ARP issue bothers me the most, just would like to know if 02 can fix it if not - seems downgrade is solution for me
I had the exact same issues, reverted to 19.07 and just keeping track in this thread, but will stick it out until there is better news.
I don't see why we would have to upgrade, new stuff is interesting, but not necessary, especially when the newer version has critical issues.
Not bashing the OpenWRT community or anything, this Linksys hardware is just a hard one to support it seems.
That being said, if you have issues with 21.02.X revert to 19.07.X for the time being and your issues will be gone. As long as both still get critical updates, there is no reason not to.
@dgilman @WildByDesign
Feel free to build and test branch gvalkov on my fork where the 5 GHz radio should work correctly. I use channel 100, 160 MHz, though my laptop only supports 80.
httpstorm/OpenWRT branch gvalkov
Or use the image I compiled
WRT3200ACM 2022-02-13.r18804 firmware
Important: before upgrade, if you choose to keep the old configuration, make sure to edit /etc/config/network, and add option device 'wan' under config interface 'wan', as well as list ports 'lan' under
config device
option name 'br-lan'
.
...although illegally in many countries
Disabling the mandatory DFS testing and going over the allowed transmit power limits is not a real solution for general usage.
I am just trying to figure out from the five commits if there is any actual fix (in addition to mangling the power table and country regdb). Possibly the few instances of patched case NL80211_CHAN_WIDTH_160 sections are actually interesting?