On 2010-09-22 6:33 AM, Ben Greear wrote: > On 09/21/2010 03:41 PM, Felix Fietkau wrote: >> On 2010-09-21 10:19 PM, Ben Greear wrote: >>> On 09/21/2010 12:32 PM, Felix Fietkau wrote: >>>> On 2010-09-21 9:28 PM, Johannes Berg wrote: >>>>> On Tue, 2010-09-21 at 20:00 +0200, Felix Fietkau wrote: >>>>> >>>>>>> Could we just poke a pointer to the STA into the ath_buf structure? >>>>> >>>>>> No, that doesn't work because of RCU. >>>>> >>>>> Well, it could work, if you walk all the structures upon sta_notify and >>>>> remove now stale pointers (or just drop the frames or something). >>>> I think it would be much better to just add the helper function that >>>> checks the RA on STA lookup. Keeps things simple, especially since >>>> nothing else in the tx path needs the vif. >>> >>> How about this. Seems to do the trick on my system: >>> >>> >>> diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c >>> index 85a7323..09815a1 100644 >>> --- a/drivers/net/wireless/ath/ath9k/xmit.c >>> +++ b/drivers/net/wireless/ath/ath9k/xmit.c >>> @@ -328,8 +328,7 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq, >>> >>> rcu_read_lock(); >>> >>> - /* XXX: use ieee80211_find_sta! */ >>> - sta = ieee80211_find_sta_by_hw(hw, hdr->addr1); >>> + sta = tx_info->control.sta; >> As I mentioned in another email: at the time we get the tx status >> report, we have to consider the sta pointer stale. It may or may not >> still be valid. > > How about this one. I think it ensures that the sta will never be stale, No, it doesn't. At least not in AP mode. > since it flushes the tx queue on vif removal. Minimal testing shows it > working, but of course I might be missing something. In AP mode, a vif has multiple sta. And draining the queue when a sta gets removed is not a good idea. - Felix -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
