TP-LINK RE200 problem with the operation of the WLAN chipset. OpenWRT rel 21.02rc4

[WodnyTraper]

Hello colleagues.

I have a TP-LINK RE200 v2.1 repeater based on the mediatek MT7628AN chipset and MT76x8AN and MT7610EN chipsets for WLAN. I am using OpenWRT image 21.02rc4. I came across a problem already described on many forums, the critical instability and the disappearance of SSID broadcasting in the 5GHz network. It is practically impossible to use now. The problems vary, but clearly indicate a driver error for this chipset. Maybe one of my fellow developers could help to solve this problem. Or one of you has found a solution to this problem.

[ArtemiisFowl]

same problem on higher channels like 120? I encounter this problem in lower channels but didn't know if it's up to me.

[WodnyTraper]

from what I read, this chip currently works best on the auto setting and then there is channel 36, and high channels such as No. 120 the chipset probably does not support and may be problematic for other devices

[mrkiko]

Ok, I am sorry if I am little bit repetitive here but - may you try latest OpenWRt HEAD?
I am hoping commit 645eac6 fixes your issue.
It would be great if you can report back! :)

[WodnyTraper]

Thank you. I need a hint which version to use? I prepare the image on 21.02 rc4 normally. Are they newer? Alternatively, I will ask for a hint on how to use what you propose.

[dmsza]

Ok, I am sorry if I am little bit repetitive here but - may you try latest OpenWRt HEAD? I am hoping commit 645eac6 fixes your issue. It would be great if you can report back! :)

Unfortunately this fix did not solve the 5Ghz issue with RE200 v2. I just did a snapshot build today (Nov 13th 2021) from master/head, and the 5Ghz Max Tx Power is still capped at 8/9dBm which makes it unusable, as can be seen below.

BusyBox v1.34.1 (2021-11-13 20:29:41 UTC) built-in shell (ash)

  _______                     ________        __
 |       |.-----.-----.-----.|  |  |  |.----.|  |_
 |   -   ||  _  |  -__|     ||  |  |  ||   _||   _|
 |_______||   __|_____|__|__||________||__|  |____|
          |__| W I R E L E S S   F R E E D O M
 -----------------------------------------------------
 OpenWrt SNAPSHOT, r18084-b5ab6d0bc5
 -----------------------------------------------------
root@ap6:~# cat /proc/cpuinfo | grep machine
machine                 : TP-Link RE200 v2
root@ap6:~# iw phy phy1 channels
Band 2:
        * 5180 MHz [36]
          Maximum TX power: 9.0 dBm
          Channel widths: 20MHz HT40+ VHT80
        * 5200 MHz [40]
          Maximum TX power: 9.0 dBm
          Channel widths: 20MHz HT40- HT40+ VHT80
        * 5220 MHz [44]
          Maximum TX power: 8.0 dBm
          Channel widths: 20MHz HT40- HT40+ VHT80
        * 5240 MHz [48]
          Maximum TX power: 8.0 dBm
          Channel widths: 20MHz HT40- HT40+ VHT80
        * 5260 MHz [52]
          Maximum TX power: 8.0 dBm
          No IR
          Radar detection
          Channel widths: 20MHz HT40- HT40+ VHT80
          DFS state: usable (for 779 sec)
          DFS CAC time: 60000 ms
        * 5280 MHz [56]
          Maximum TX power: 8.0 dBm
          No IR
          Radar detection
          Channel widths: 20MHz HT40- HT40+ VHT80
          DFS state: usable (for 779 sec)
          DFS CAC time: 60000 ms
        * 5300 MHz [60]
          Maximum TX power: 8.0 dBm
          No IR
          Radar detection
          Channel widths: 20MHz HT40- HT40+ VHT80
          DFS state: usable (for 779 sec)
          DFS CAC time: 60000 ms
        * 5320 MHz [64]
          Maximum TX power: 8.0 dBm
          No IR
          Radar detection
          Channel widths: 20MHz HT40- VHT80
          DFS state: usable (for 779 sec)
          DFS CAC time: 60000 ms
        * 5500 MHz [100]
          Maximum TX power: 8.0 dBm
          No IR
          Radar detection
          Channel widths: 20MHz HT40+ VHT80
          DFS state: usable (for 779 sec)
          DFS CAC time: 60000 ms
        * 5520 MHz [104]
          Maximum TX power: 8.0 dBm
          No IR
          Radar detection
          Channel widths: 20MHz HT40- HT40+ VHT80
          DFS state: usable (for 779 sec)
          DFS CAC time: 60000 ms
        * 5540 MHz [108]
          Maximum TX power: 8.0 dBm
          No IR
          Radar detection
          Channel widths: 20MHz HT40- HT40+ VHT80
          DFS state: usable (for 779 sec)
          DFS CAC time: 60000 ms
        * 5560 MHz [112]
          Maximum TX power: 8.0 dBm
          No IR
          Radar detection
          Channel widths: 20MHz HT40- HT40+ VHT80
          DFS state: usable (for 779 sec)
          DFS CAC time: 60000 ms
        * 5580 MHz [116]
          Maximum TX power: 8.0 dBm
          No IR
          Radar detection
          Channel widths: 20MHz HT40- HT40+ VHT80
          DFS state: usable (for 779 sec)
          DFS CAC time: 60000 ms
        * 5600 MHz [120]
          Maximum TX power: 8.0 dBm
          No IR
          Radar detection
          Channel widths: 20MHz HT40- HT40+ VHT80
          DFS state: usable (for 779 sec)
          DFS CAC time: 60000 ms
        * 5620 MHz [124]
          Maximum TX power: 8.0 dBm
          No IR
          Radar detection
          Channel widths: 20MHz HT40- HT40+ VHT80
          DFS state: usable (for 779 sec)
          DFS CAC time: 60000 ms
        * 5640 MHz [128]
          Maximum TX power: 8.0 dBm
          No IR
          Radar detection
          Channel widths: 20MHz HT40- HT40+ VHT80
          DFS state: usable (for 779 sec)
          DFS CAC time: 60000 ms
        * 5660 MHz [132]
          Maximum TX power: 8.0 dBm
          No IR
          Radar detection
          Channel widths: 20MHz HT40- HT40+ VHT80
          DFS state: usable (for 779 sec)
          DFS CAC time: 60000 ms
        * 5680 MHz [136]
          Maximum TX power: 8.0 dBm
          No IR
          Radar detection
          Channel widths: 20MHz HT40- HT40+ VHT80
          DFS state: usable (for 779 sec)
          DFS CAC time: 60000 ms
        * 5700 MHz [140]
          Maximum TX power: 8.0 dBm
          No IR
          Radar detection
          Channel widths: 20MHz HT40- HT40+ VHT80
          DFS state: usable (for 779 sec)
          DFS CAC time: 60000 ms
        * 5720 MHz [144]
          Maximum TX power: 8.0 dBm
          No IR
          Radar detection
          Channel widths: 20MHz HT40- VHT80
          DFS state: usable (for 779 sec)
          DFS CAC time: 60000 ms
        * 5745 MHz [149]
          Maximum TX power: 8.0 dBm
          No IR
          Channel widths: 20MHz HT40+ VHT80
        * 5765 MHz [153]
          Maximum TX power: 9.0 dBm
          No IR
          Channel widths: 20MHz HT40- HT40+ VHT80
        * 5785 MHz [157]
          Maximum TX power: 9.0 dBm
          No IR
          Channel widths: 20MHz HT40- HT40+ VHT80
        * 5805 MHz [161]
          Maximum TX power: 9.0 dBm
          No IR
          Channel widths: 20MHz HT40- HT40+ VHT80
        * 5825 MHz [165]
          Maximum TX power: 9.0 dBm
          No IR
          Channel widths: 20MHz HT40- VHT80
        * 5845 MHz [169] (disabled)
        * 5865 MHz [173] (disabled)
root@ap6:~#

[phpaiva]

You can check this topic and my last posts, maybe is a useful hint for someone. I find diffent behaviors between suposed exactly same devices and firmwares, but by using that Oct 2020 snapshot (r14820-5cdc65f6d1) and leaving a task in crontab or a service which issues the commands I used every sec, 5 sec or per minute you get the device in fine operating conditions (also AP+STA mode in 5 GHz). My current script is:

while true

  do

	  sleep 1
	  cd /sys/kernel/debug/ieee80211/phy1/mt76
	  echo 0x13b0 > regidx
	  echo 0x2f2f1414 > regval
	  echo 0x2320 > regidx
	  echo 0x122c3cf2 > regval

  done

It's a shame, but it seems that somewhen between that snapshot and the next OWRT release they ruined something which is more than just a Tx power issue.

The main problem in my case is that I do not understand what I am really doing, nobody seems yo be able to answer and I find a random behavior between devices which seem to be equal in hardware and firmware.

#633 (comment)

[brada4]

The tx power is half (rounded down) in dBm of what regdom ordered.
iw list

                Frequencies:
                        * 5180 MHz [36] (12.0 dBm)
                        * 5200 MHz [40] (12.0 dBm)
                        * 5220 MHz [44] (11.0 dBm)
                        * 5240 MHz [48] (11.0 dBm)
                        * 5260 MHz [52] (11.0 dBm) (radar detection)
                        * 5280 MHz [56] (11.0 dBm) (radar detection)
                        * 5300 MHz [60] (11.0 dBm) (radar detection)
                        * 5320 MHz [64] (10.0 dBm) (radar detection)
                        * 5500 MHz [100] (11.0 dBm) (radar detection)
                        * 5520 MHz [104] (12.0 dBm) (radar detection)
                        * 5540 MHz [108] (12.0 dBm) (radar detection)
                        * 5560 MHz [112] (12.0 dBm) (radar detection)
                        * 5580 MHz [116] (12.0 dBm) (radar detection)
                        * 5600 MHz [120] (13.0 dBm) (radar detection)
                        * 5620 MHz [124] (13.0 dBm) (radar detection)
                        * 5640 MHz [128] (13.0 dBm) (radar detection)
                        * 5660 MHz [132] (13.0 dBm) (radar detection)
                        * 5680 MHz [136] (13.0 dBm) (radar detection)
                        * 5700 MHz [140] (13.0 dBm) (radar detection)
                        * 5720 MHz [144] (13.0 dBm) (radar detection)
                        * 5745 MHz [149] (13.0 dBm)
                        * 5765 MHz [153] (13.0 dBm)
                        * 5785 MHz [157] (13.0 dBm)
                        * 5805 MHz [161] (13.0 dBm)
                        * 5825 MHz [165] (13.0 dBm)
                        * 5845 MHz [169] (6.0 dBm)
                        * 5865 MHz [173] (6.0 dBm)

iw reg get

global
country BE: DFS-ETSI
        (2400 - 2483 @ 40), (N/A, 20), (N/A)
        (5150 - 5250 @ 80), (N/A, 23), (N/A), NO-OUTDOOR, AUTO-BW
        (5250 - 5350 @ 80), (N/A, 20), (0 ms), NO-OUTDOOR, DFS, AUTO-BW
        (5470 - 5725 @ 160), (N/A, 26), (0 ms), DFS
        (5725 - 5875 @ 80), (N/A, 13), (N/A)
        (5945 - 6425 @ 160), (N/A, 23), (N/A), NO-OUTDOOR
        (57000 - 66000 @ 2160), (N/A, 40), (N/A)