[ath9k-devel] Strange reception problem with ar9285

[Holger Schurig <holgerschurig@googlemail.com>]

I peppered my code with debug statements. "##HS blah:123" means
function "blah()", line 123 in my source code
(compat-wireless-2012-05-08).

This log is from my office, where I didn't had a problem. Some
questions after the log:

ath9k 0000:01:00.0: PCI INT A -> GSI 16 (level, low) -> IRQ 16
ath9k 0000:01:00.0: setting latency timer to 64
##HS ath9k_set_hw_capab:723 rx 0x1, tx 0x1
##HS ath9k_set_hw_capab:729
ath: EEPROM regdomain: 0x60
ath: EEPROM indicates we should expect a direct regpair map
ath: Country alpha2 being used: 00
ath: Regpair used: 0x60
ieee80211 phy1: Selected rate control algorithm 'ath9k_rate_control'
Registered led device: ath9k-phy1
ieee80211 phy1: Atheros AR9285 Rev:2 mem=0xf8e60000, irq=16
ieee80211 phy1: device now idle
##HS ath9k_get_antenna:2392 rx 0x3, tx 0x1
##HS ath9k_get_antenna:2392 rx 0x3, tx 0x1
ieee80211 phy1: device no longer idle - scanning
##HS ath_rx_tasklet:1969 change def rx ant
##HS ath9k_hw_setantenna: 0x1
##HS ath_setdefantenna:113
ieee80211 phy1: device now idle
wlan0: authenticate with 00:a0:57:15:ba:0d
ieee80211 phy1: Allocated STA 00:a0:57:15:ba:0d
ieee80211 phy1: device no longer idle - in use
ieee80211 phy1: Inserted STA 00:a0:57:15:ba:0d
wlan0: send auth to 00:a0:57:15:ba:0d (try 1/3)
wlan0: authenticated
wlan0: moving STA 00:a0:57:15:ba:0d to state 2
wlan0: associate with 00:a0:57:15:ba:0d (try 1/3)
wlan0: RX AssocResp from 00:a0:57:15:ba:0d (capab=0x11 status=0 aid=1)
wlan0: associated
wlan0: moving STA 00:a0:57:15:ba:0d to state 3
wlan0: moving STA 00:a0:57:15:ba:0d to state 4

I don't know the hardware at all. What makes me wonder is this: in
ath9k_set_hw_capab() I print the contents of
hw->wiphy->available_antennas_rx and hw->wiphy->available_antennas_tx.
Both are one. So I assume I only have one antenna, or?

Later the code finds out that ATH9K_HW_CAP_ANT_DIV_COMB is set and
adds a second receive antenna. What is ATH9K_HW_CAP_ANT_DIV_COMB?
And, what would happen if my hardware only has one antenna, but this
capability if falsely set?