Hi,
I've recently updated my Redmi AC2100 with a custom build of OpenWrt.
Just after update I noticed that the 5GHz radio has the txpower capped at 6dbm, while it was higher before the update.
The 2.4GHz channels are OK with my regulatory domains (20dbm for Italy).
This is the output of iw list:
Wiphy phy1
wiphy index: 1
max # scan SSIDs: 4
max scan IEs length: 2304 bytes
max # sched scan SSIDs: 0
max # match sets: 0
Retry short limit: 7
Retry long limit: 4
Coverage class: 0 (up to 0m)
Device supports AP-side u-APSD.
Device supports T-DLS.
Available Antennas: TX 0xf RX 0xf
Configured Antennas: TX 0xf RX 0xf
Supported interface modes:
* IBSS
* managed
* AP
* AP/VLAN
* monitor
* mesh point
* P2P-client
* P2P-GO
Band 2:
Capabilities: 0x1ff
RX LDPC
HT20/HT40
SM Power Save disabled
RX Greenfield
RX HT20 SGI
RX HT40 SGI
TX STBC
RX STBC 1-stream
Max AMSDU length: 3839 bytes
No DSSS/CCK HT40
Maximum RX AMPDU length 65535 bytes (exponent: 0x003)
Minimum RX AMPDU time spacing: No restriction (0x00)
HT TX/RX MCS rate indexes supported: 0-31
VHT Capabilities (0x338001f8):
Max MPDU length: 3895
Supported Channel Width: 160 MHz, 80+80 MHz
RX LDPC
short GI (80 MHz)
short GI (160/80+80 MHz)
TX STBC
RX antenna pattern consistency
TX antenna pattern consistency
VHT RX MCS set:
1 streams: MCS 0-9
2 streams: MCS 0-9
3 streams: MCS 0-9
4 streams: MCS 0-9
5 streams: not supported
6 streams: not supported
7 streams: not supported
8 streams: not supported
VHT RX highest supported: 0 Mbps
VHT TX MCS set:
1 streams: MCS 0-9
2 streams: MCS 0-9
3 streams: MCS 0-9
4 streams: MCS 0-9
5 streams: not supported
6 streams: not supported
7 streams: not supported
8 streams: not supported
VHT TX highest supported: 0 Mbps
Frequencies:
* 5180 MHz [36] (6.0 dBm)
* 5200 MHz [40] (6.0 dBm)
* 5220 MHz [44] (6.0 dBm)
* 5240 MHz [48] (6.0 dBm)
* 5260 MHz [52] (6.0 dBm) (radar detection)
* 5280 MHz [56] (6.0 dBm) (radar detection)
* 5300 MHz [60] (6.0 dBm) (radar detection)
* 5320 MHz [64] (6.0 dBm) (radar detection)
* 5500 MHz [100] (6.0 dBm) (radar detection)
* 5520 MHz [104] (6.0 dBm) (radar detection)
* 5540 MHz [108] (6.0 dBm) (radar detection)
* 5560 MHz [112] (6.0 dBm) (radar detection)
* 5580 MHz [116] (6.0 dBm) (radar detection)
* 5600 MHz [120] (6.0 dBm) (radar detection)
* 5620 MHz [124] (6.0 dBm) (radar detection)
* 5640 MHz [128] (6.0 dBm) (radar detection)
* 5660 MHz [132] (6.0 dBm) (radar detection)
* 5680 MHz [136] (6.0 dBm) (radar detection)
* 5700 MHz [140] (6.0 dBm) (radar detection)
* 5720 MHz [144] (6.0 dBm) (radar detection)
* 5745 MHz [149] (6.0 dBm)
* 5765 MHz [153] (6.0 dBm)
* 5785 MHz [157] (6.0 dBm)
* 5805 MHz [161] (6.0 dBm)
* 5825 MHz [165] (6.0 dBm)
* 5845 MHz [169] (6.0 dBm)
* 5865 MHz [173] (6.0 dBm)
valid interface combinations:
* #{ IBSS } <= 1, #{ managed, AP, mesh point, P2P-client, P2P-GO } <= 16,
total <= 16, #channels <= 1, STA/AP BI must match, radar detect widths: { 20 MHz (no HT), 20 MHz, 40 MHz, 80 MHz, 80+80 MHz, 160 MHz }
HT Capability overrides:
* MCS: ff ff ff ff ff ff ff ff ff ff
* maximum A-MSDU length
* supported channel width
* short GI for 40 MHz
* max A-MPDU length exponent
* min MPDU start spacing
max # scan plans: 1
max scan plan interval: 0
max scan plan iterations: 0
Supported extended features:
* [ VHT_IBSS ]: VHT-IBSS
* [ RRM ]: RRM
* [ SET_SCAN_DWELL ]: scan dwell setting
* [ FILS_STA ]: STA FILS (Fast Initial Link Setup)
* [ CQM_RSSI_LIST ]: multiple CQM_RSSI_THOLD records
* [ CONTROL_PORT_OVER_NL80211 ]: control port over nl80211
* [ TXQS ]: FQ-CoDel-enabled intermediate TXQs
* [ AIRTIME_FAIRNESS ]: airtime fairness scheduling
* [ AQL ]: Airtime Queue Limits (AQL)
* [ CONTROL_PORT_NO_PREAUTH ]: disable pre-auth over nl80211 control port support
* [ DEL_IBSS_STA ]: deletion of IBSS station support
* [ SCAN_FREQ_KHZ ]: scan on kHz frequency support
* [ CONTROL_PORT_OVER_NL80211_TX_STATUS ]: tx status for nl80211 control port support
Wiphy phy0
wiphy index: 0
max # scan SSIDs: 4
max scan IEs length: 2257 bytes
max # sched scan SSIDs: 0
max # match sets: 0
Retry short limit: 7
Retry long limit: 4
Coverage class: 0 (up to 0m)
Device supports AP-side u-APSD.
Device supports T-DLS.
Available Antennas: TX 0x3 RX 0x3
Configured Antennas: TX 0x3 RX 0x3
Supported interface modes:
* IBSS
* managed
* AP
* AP/VLAN
* monitor
* mesh point
* P2P-client
* P2P-GO
Band 1:
Capabilities: 0x1fe
HT20/HT40
SM Power Save disabled
RX Greenfield
RX HT20 SGI
RX HT40 SGI
TX STBC
RX STBC 1-stream
Max AMSDU length: 3839 bytes
No DSSS/CCK HT40
Maximum RX AMPDU length 65535 bytes (exponent: 0x003)
Minimum RX AMPDU time spacing: No restriction (0x00)
HT TX/RX MCS rate indexes supported: 0-15
Frequencies:
* 2412 MHz [1] (20.0 dBm)
* 2417 MHz [2] (20.0 dBm)
* 2422 MHz [3] (20.0 dBm)
* 2427 MHz [4] (20.0 dBm)
* 2432 MHz [5] (20.0 dBm)
* 2437 MHz [6] (20.0 dBm)
* 2442 MHz [7] (20.0 dBm)
* 2447 MHz [8] (20.0 dBm)
* 2452 MHz [9] (20.0 dBm)
* 2457 MHz [10] (20.0 dBm)
* 2462 MHz [11] (20.0 dBm)
* 2467 MHz [12] (20.0 dBm)
* 2472 MHz [13] (20.0 dBm)
* 2484 MHz [14] (disabled)
valid interface combinations:
* #{ IBSS } <= 1, #{ managed, AP, mesh point, P2P-client, P2P-GO } <= 4,
total <= 4, #channels <= 1, STA/AP BI must match
HT Capability overrides:
* MCS: ff ff ff ff ff ff ff ff ff ff
* maximum A-MSDU length
* supported channel width
* short GI for 40 MHz
* max A-MPDU length exponent
* min MPDU start spacing
max # scan plans: 1
max scan plan interval: -1
max scan plan iterations: 0
Supported extended features:
* [ RRM ]: RRM
* [ FILS_STA ]: STA FILS (Fast Initial Link Setup)
* [ CQM_RSSI_LIST ]: multiple CQM_RSSI_THOLD records
* [ CONTROL_PORT_OVER_NL80211 ]: control port over nl80211
* [ TXQS ]: FQ-CoDel-enabled intermediate TXQs
* [ AIRTIME_FAIRNESS ]: airtime fairness scheduling
* [ AQL ]: Airtime Queue Limits (AQL)
* [ SCAN_RANDOM_SN ]: use random sequence numbers in scans
* [ SCAN_MIN_PREQ_CONTENT ]: use probe request with only rate IEs in scans
* [ CONTROL_PORT_NO_PREAUTH ]: disable pre-auth over nl80211 control port support
* [ DEL_IBSS_STA ]: deletion of IBSS station support
* [ SCAN_FREQ_KHZ ]: scan on kHz frequency support
* [ CONTROL_PORT_OVER_NL80211_TX_STATUS ]: tx status for nl80211 control port support
Searching in the forum I've found that this could be caused by bad blocks in the calibration/RF section of the EEPROM. This is discussed for example in:
- https://forum.openwrt.org/t/r6800-transmission-power-max-6dbm/96537
- https://forum.openwrt.org/t/netgear-r6850-very-low-transmit-power-on-5ghz/90984
- https://github.com/openwrt/mt76/issues/376
Unfortunately I cannot find the backups of my EEPROM and I cannot reflash the old one.
I was wondering if anyone has some suggestions on how to investigate if this is indeed the problem, how to fix it or if someone has a dump of the EEPROM that I can use to test.
Thanks
Marco