[ath9k-devel] Incorrect TX statistics

[Michal Kudelski <michal@idsia.ch>]

Hi All,

I still can't solve my problem with incorrect TX status 
info in ath9k_htc driver.

 From the MAC layer, I need the information about the 
status of a single packet transmission. I am interested 
only in data packets, and only in 'unicast' transmissions, 
so it is a matter of information whether the perception of 
the packet has been confirmed by the receiver (by ACK). I 
work in "Ad Hoc" mode (but the problem relates to the 
access point mode as well - statistics displayed by the 
Linux system always show 100% of correct transmissions).

It seems that the MAC layer in Linux is not properly 
informed about the status of transmission: in the 
"ieee80211_tx_status" function, being called by the device 
driver, a flag "IEEE80211_TX_STAT_ACK" is always set, 
regardless of whether the packet arrived to the recipient 
or not.

I use:
  - TP-LINK TL-WN722N
  - "Ad-Hoc" mode
  - compat-wireless-3.6.2-1 [but it's the same with the 
latest compat-drivers-3.9-rc4-2-su]

Could you please help? If this requires some changes in 
the driver/firmware, I'm ready to give it a try, and to 
propose a fixing patch for this, but I need some info on 
where to start... Or maybe it's my device that does not 
work properly (it seems to me that ACKs are handled by the 
internal CPU of TL-WN722N, and I'm not sure if the status 
is propagated to the higher layers...)?

Best regards,
Michal Kudelski