Antenna Configuration Question

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28-02-2008 00:17:47

Is there anywhere that the Tx antenna gets selected for rt73 or rt61?

I was wondering if the reason that rt73 fails to transmit anything despite looking like it is transmitting could be antenna config related but I can't find anything that actually controls the Tx antenna (as opposed to the eeprom which just says what it should be).

I've attached the script I've written to start decoding register values in case it is any use to anyone else. It works out what both antennas should be and reads R77 to reveal what the Rx antenna is up to but I can't find anything for Tx antenna. Looking through register definitions I can see some retry stats that might be useful to add to this.

I've also had a further look at the problem with rt61 dying while running. It looks as though when it dies Tx queue 2 stops receiving new packets but Tx queue 0 and the Rx queue are still operating correctly. I wonder if the queue full situation isn't being handled correctly.


01-03-2008 13:41:59

Hello Adam,

i have executed your script, works well D

This is a rt61pci MIMO card with 3 Antennas.
More info below.

# ./
using path /proc/sys/debug/ieee80211/phy0/rt61pci/register
Num Antennas = 2
Tx Default = 1 Antenna A
Rx Default = 1 Antenna A
Antenna Control = 1
Current Rx Antenna = 3
sensitivity = 79

# iwconfig
wmaster0 no wireless extensions.

wlan0 IEEE 802.11 ESSID""
ModeManaged Frequency2.412 GHz Access Point Not-Associated
Tx-Power=1 dBm
Retry min limit7 RTS throff Fragment thr=2352 B
Encryption keyoff
Link Quality0 Signal level0 Noise level0
Rx invalid nwid0 Rx invalid crypt0 Rx invalid frag0
Tx excessive retries0 Invalid misc0 Missed beacon0

# dmesg
phy0 -> rt61pci_validate_eeprom EEPROM recovery - Led 0xe0ff
phy0 -> rt61pci_validate_eeprom EEPROM recovery - RSSI OFFSET BG 0x0000
phy0 -> rt61pci_validate_eeprom EEPROM recovery - RSSI OFFSET A 0x0000
phy0 -> rt2x00_set_chip Info - Chipset detected - rt 0401, rf 0004, rev 0002661d.
phy0 Selected rate control algorithm 'pid'
Registered led device rt61pci-phy0radio
Registered led device rt61pci-phy0assoc
phy0 -> rt2x00lib_request_firmware Info - Loading firmware file 'rt2661.bin'.
phy0 -> rt2x00lib_request_firmware Info - Firmware detected - version 0.8.

# lspci
0012.0 Network controller RaLink RT2600 802.11 MIMO

# lspci -n
0012.0 0280 18140401

Tell me if i can help with testing.

This is on current rt2x00.git version 2.1.3