RT-AC68U, 386_49703 and 2.4GHz G/N only mode

sfx2000

Part of the Furniture
Ran into an interesting thing helping out a remote family member - 100 percent reproducible...

Stock RT-AC68U, FW 386_49707 (happened on Merlin 387_2 as well) -

configure the 2.4GHz radio as default and check the "Disable 11b" box (basically this turns off supposedly the DSSS capability, so OFDM only, and basic rates are 6, 12, 24)

Router Side...

Code:
Sep  9 13:20:05 syslog: wlceventd_proc_event(559): eth1: Assoc 4C:1D:96:F0:D1:AB, status: Successful (0), rssi:0
Sep  9 13:20:06 syslog: wlceventd_proc_event(494): eth1: Deauth_ind 4C:1D:96:F0:D1:AB, status: 0, reason: Disassociated due to inactivity (4), rssi:0
Sep  9 13:20:16 syslog: wlceventd_proc_event(530): eth1: Auth 4C:1D:96:F0:D1:AB, status: Successful (0), rssi:0
Sep  9 13:20:16 syslog: wlceventd_proc_event(559): eth1: Assoc 4C:1D:96:F0:D1:AB, status: Successful (0), rssi:0
Sep  9 13:20:16 syslog: wlceventd_proc_event(494): eth1: Deauth_ind 4C:1D:96:F0:D1:AB, status: 0, reason: Disassociated due to inactivity (4), rssi:0

Chromebook Side

Code:
[ 2314.297464] wlan0: authenticate with 78:24:af:7a:5a:80
[ 2314.297482] wlan0: bad VHT capabilities, disabling VHT
[ 2314.297484] wlan0: 80 MHz not supported, disabling VHT
[ 2314.306880] wlan0: send auth to 78:24:af:7a:5a:80 (try 1/3)
[ 2314.345448] wlan0: authenticated
[ 2314.346453] wlan0: associate with 78:24:af:7a:5a:80 (try 1/3)
[ 2314.347444] wlan0: RX AssocResp from 78:24:af:7a:5a:80 (capab=0x1411 status=0 aid=1)
[ 2314.349254] wlan0: associated
[ 2314.921135] iwlwifi 0000:01:00.0: No beacon heard and the time event is over already...
[ 2314.921230] wlan0: Connection to AP 78:24:af:7a:5a:80 lost
[ 2324.359542] wlan0: authenticate with 78:24:af:7a:5a:80
[ 2324.359562] wlan0: bad VHT capabilities, disabling VHT
[ 2324.359565] wlan0: 80 MHz not supported, disabling VHT
[ 2324.371343] wlan0: send auth to 78:24:af:7a:5a:80 (try 1/3)
[ 2324.408946] wlan0: authenticated
[ 2324.409622] wlan0: associate with 78:24:af:7a:5a:80 (try 1/3)
[ 2324.410654] wlan0: RX AssocResp from 78:24:af:7a:5a:80 (capab=0x1411 status=0 aid=1)
[ 2324.412413] wlan0: associated
[ 2324.985561] iwlwifi 0000:01:00.0: No beacon heard and the time event is over already...
[ 2324.986653] wlan0: Connection to AP 78:24:af:7a:5a:80 lost

Basically the client Station is losing the beacon in the G/N mode with the iwlwfi driver - ath10k looks ok, no issues noted there as I've confirmed with a ubuntu box... I don't have a linux box with an intel wifi card, but Windows 10 and AX201 was fine...

Setting up the same mode/setup on my ath9k openwrt dev unit on my desk here, and it's fine as well.

The fix is to uncheck the "disable 11b", and things work again - I do think this is likely a bug in the intel driver, but still important to note.

hope this helps someone...
 

sfx2000

Part of the Furniture
and FWIW - this is a red herring...

Code:
[ 2314.297482] wlan0: bad VHT capabilities, disabling VHT
[ 2314.297484] wlan0: 80 MHz not supported, disabling VHT

There are no VHT elements in the Asus beacon, and I see the same log items with other AP's - Atheros, mediatek, Marvell, Broadcom...
 

sfx2000

Part of the Furniture
Changed the thread title - it's a Broadcom WL driver bug as near as I can tell - confirmed with linux ath9k, ath10k, and iwlwifi client stations - noted first on ChromeOS with Intel - but confirmed on debian and ubunty jammy...

@RMerlin - affects your build as well, which makes sense, as this is Broadcom's SDK - someone from Asus that has insight int the wl driver will have to debug.

Short term fix would be to remove the feature - actually the html markup would be sufficient.
 

RMerlin

Asuswrt-Merlin dev
Use the Feedback form on the router to report it to Asus.

Considering the age of the SDK6.37 used by the RT-AC68U, I suspect it's been EOL from Broadcom for quite some time already.
 

sfx2000

Part of the Furniture
Use the Feedback form on the router to report it to Asus.

I'm not releasing SW based on their GPL - I suggest you review and forward, as it impacts your release as well.

Consider the bug reported.
 

RMerlin

Asuswrt-Merlin dev
I'm not releasing SW based on their GPL - I suggest you review and forward, as it impacts your release as well.
And I have zero motivation to act as your liaison with Asus for bugs that you have found (or believe to have found), and having to devote my time going back and forth between you two. I already have too much on my plate as it is. So, you will have to decide for yourself how badly you want this addressed. The feedback form is there right in the router's webui for that kind of report.
 

sfx2000

Part of the Furniture
Eric - i have zero skin in this game... if it were a bug in my code, I would say thank you and move on.

This bug impacts your code - consider that carefully in your response here...

With the complexity that is with AsusWRT - the best thing i can recommend is to remove this feature via WebUI mark-up until that upstream folks can find a fix with the broadcom driver.

'nuff said
 

Similar threads

Sign Up For SNBForums Daily Digest

Get an update of what's new every day delivered to your mailbox. Sign up here!
Top