[SOLVED] MT7620A RX path issue

Hi

as you can see the list of devices that have bad reception on mt7620a wifi increases and the following ones are confirmed to be affected:

Xiaomi Mini
Lenovo Y1
NEXX WT3020

according to eeprom xiaomi should have external LNA, but what is the RF design on wt3020?

as lenovo hasn't got eLNA seems like this affects all devices?

anyone got some clue how to solve this problem?

the issues described in these topics:

https://forum.openwrt.org/viewtopic.php?id=69042

https://forum.openwrt.org/viewtopic.php?id=66905

having 5 VAPs running on startup revealed some tx queue reconfiguration:

[   24.950869] ieee80211 phy1: rt2x00mac_conf_tx: Warning - Configured TX queue 0 - CWmin: 2, CWmax: 3, Aifs: 2, TXop: 47
[   24.961844] ieee80211 phy1: rt2x00mac_conf_tx: Warning - Configured TX queue 1 - CWmin: 3, CWmax: 4, Aifs: 2, TXop: 94
[   24.972785] ieee80211 phy1: rt2x00mac_conf_tx: Warning - Configured TX queue 2 - CWmin: 4, CWmax: 10, Aifs: 3, TXop: 0
[   24.983735] ieee80211 phy1: rt2x00mac_conf_tx: Warning - Configured TX queue 3 - CWmin: 4, CWmax: 10, Aifs: 7, TXop: 0
[   26.943987] ieee80211 phy1: rt2x00mac_conf_tx: Warning - Configured TX queue 0 - CWmin: 2, CWmax: 3, Aifs: 2, TXop: 47
[   26.954991] ieee80211 phy1: rt2x00mac_conf_tx: Warning - Configured TX queue 1 - CWmin: 3, CWmax: 4, Aifs: 2, TXop: 94
[   26.965936] ieee80211 phy1: rt2x00mac_conf_tx: Warning - Configured TX queue 2 - CWmin: 4, CWmax: 10, Aifs: 3, TXop: 0
[   26.976873] ieee80211 phy1: rt2x00mac_conf_tx: Warning - Configured TX queue 3 - CWmin: 4, CWmax: 10, Aifs: 7, TXop: 0
[   28.586324] ieee80211 phy1: rt2x00mac_conf_tx: Warning - Configured TX queue 0 - CWmin: 2, CWmax: 3, Aifs: 2, TXop: 47
[   28.597322] ieee80211 phy1: rt2x00mac_conf_tx: Warning - Configured TX queue 1 - CWmin: 3, CWmax: 4, Aifs: 2, TXop: 94
[   28.608274] ieee80211 phy1: rt2x00mac_conf_tx: Warning - Configured TX queue 2 - CWmin: 4, CWmax: 10, Aifs: 3, TXop: 0
[   28.619212] ieee80211 phy1: rt2x00mac_conf_tx: Warning - Configured TX queue 3 - CWmin: 4, CWmax: 10, Aifs: 7, TXop: 0
[   31.534074] ieee80211 phy1: rt2x00mac_conf_tx: Warning - Configured TX queue 0 - CWmin: 2, CWmax: 3, Aifs: 2, TXop: 47
[   31.545080] ieee80211 phy1: rt2x00mac_conf_tx: Warning - Configured TX queue 1 - CWmin: 3, CWmax: 4, Aifs: 2, TXop: 94
[   31.556071] ieee80211 phy1: rt2x00mac_conf_tx: Warning - Configured TX queue 2 - CWmin: 4, CWmax: 10, Aifs: 3, TXop: 0
[   31.567157] ieee80211 phy1: rt2x00mac_conf_tx: Warning - Configured TX queue 3 - CWmin: 4, CWmax: 10, Aifs: 7, TXop: 0
[   33.965225] ieee80211 phy1: rt2x00mac_conf_tx: Warning - Configured TX queue 0 - CWmin: 2, CWmax: 3, Aifs: 2, TXop: 47
[   33.976231] ieee80211 phy1: rt2x00mac_conf_tx: Warning - Configured TX queue 1 - CWmin: 3, CWmax: 4, Aifs: 2, TXop: 94
[   33.987185] ieee80211 phy1: rt2x00mac_conf_tx: Warning - Configured TX queue 2 - CWmin: 4, CWmax: 10, Aifs: 3, TXop: 0
[   33.998132] ieee80211 phy1: rt2x00mac_conf_tx: Warning - Configured TX queue 3 - CWmin: 4, CWmax: 10, Aifs: 7, TXop: 0
[   34.167057] ieee80211 phy1: rt2x00mac_conf_tx: Warning - Configured TX queue 0 - CWmin: 2, CWmax: 3, Aifs: 1, TXop: 47
[   34.199284] ieee80211 phy1: rt2x00mac_conf_tx: Warning - Configured TX queue 1 - CWmin: 3, CWmax: 4, Aifs: 1, TXop: 94
[   34.236448] ieee80211 phy1: rt2x00mac_conf_tx: Warning - Configured TX queue 2 - CWmin: 4, CWmax: 6, Aifs: 3, TXop: 0
[   34.281246] ieee80211 phy1: rt2x00mac_conf_tx: Warning - Configured TX queue 3 - CWmin: 4, CWmax: 10, Aifs: 7, TXop: 0

after the 5th VAP was started (there is about 1-2 seconds delay between each virtual interface start) the tx queue 2 CWmax, tx queue 0 and tx queue 1 Aifs were reconfigured - you can see it happens not even 0.3 sec afterwards. could this affect rx side in any way? and why does the txqueue parameters reconfigure?

update: the problem cause - missing RF and BB registers to support external LNA

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