Re: [PATCH] ath9k: Test for TID only in BlockAcks while checking tx status

[Felix Fietkau <nbd@openwrt.org>]

On 2012-10-29 1:34 PM, Felix Fietkau wrote:
> On 2012-10-29 1:25 PM, Sven Eckelmann wrote:
>> The ath9k xmit functions for AMPDUs can send frames as non-aggregate in case
>> only one frame is currently available. The client will then answer using a
>> normal Ack instead of a BlockAck. This acknowledgement has no TID stored and
>> therefore the hardware is not able to provide us the corresponding TID.
>> 
>> The TID set by the hardware in the tx status descriptor has to be seen as
>> undefined and not as a valid TID value for normal acknowledgements. Doing
>> otherwise results in a massive amount of retransmissions and stalls of
>> connections.
>> 
>> Users may experience low bandwidth and complete connection stalls in
>> environments with transfers using multiple TIDs.
>> 
>> This regression was introduced in b11b160defc48e4daa283f785192ea3a23a51f8e
>> ("ath9k: validate the TID in the tx status information").
>> 
>> Signed-off-by: Sven Eckelmann <sven@narfation.org>
>> Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
> Nice catch, thanks!
> Acked-by: Felix Fietkau <nbd@openwrt.org>
One more thing: I think this deserves a
Cc: stable@vger.kernel.org

- Felix