Re: [ath9k-devel] ath9k, multiple stations, and AMPDUs

[Felix Fietkau <nbd@openwrt.org>]

On 2010-09-21 7:25 PM, Ben Greear wrote:
> On 09/21/2010 05:19 AM, Felix Fietkau wrote:
>> On 2010-09-21 2:08 PM, Ben Greear wrote:
> 
>>> If you have any more details on this, please let me know.  I'm going to
>>> attempt to fix it...I certainly have a good test case :)
>> ath_tx_complete_aggr completes an A-MPDU frame, which typically triggers
>> the release of the next A-MPDU to the hw queue.
>> To keep track of the Block ACK window, it needs to look up the TID, for
>> which it needs a STA pointer. At that level, the driver typically
>> doesn't have access to the vif.
>>
>> It might be possible to fix this by adding another sta lookup helper
>> function in mac80211 that takes another address argument for the BSSID,
>> so that it can get the sta entry for the correct vif. I don't know if
>> Johannes wants something like that though.
> 
> Could we just poke a pointer to the STA into the ath_buf structure?
No, that doesn't work because of RCU.

- Felix