-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Luis R. Rodriguez a écrit : > On Tue, Oct 14, 2008 at 11:29:19PM -0700, Benoit PAPILLAULT wrote: >> -----BEGIN PGP SIGNED MESSAGE----- >> Hash: SHA1 > > Hey Bonoit! > >> Hi there, >> >> I'm currently testing an AR5416 minipci card in a laptop (using 1, 2 or >> 3 antennas does not make any difference). My configuration is: >> >> - - laptop with the minipci card in STA mode >> - - Linksys WRT350N in AP mode >> - - another laptop wired to the Linksys AP >> - - doing iperf between the 2 laptops >> >> I'm using wireless-testing tree + the ath9k driver. Here are the problem >> i'm facing: >> >> 1/ Association using wpa_suplicant (WPA2-PSK) is OK > > Yay. > >> 2/ DHCP is always failing (I never got an IP) > > Thanks, this should not fail and it does not fail in my own setup. > Can you provide the log messages during this? > >> 3/ Using a fixed IP, I'm not able to ping for some time (at least for 80s) > > This needs to be fixed too, can you provide log messages during this? > I haven't seen this anymore, it used to happen but I no longer see it. > >> 4/ When ping is working, throughout is like 15 Mbits at its maximum. > > You will only get MCS rates but without aggregation. It also depends > on the noise on the location of where you are testing. More on this below. > >> 5/ During all the test, tcpdump show that the RX side is OK >> >> dmesg shows lots of "BA request denied", but apparently that might not >> be a problem. > > Out of these I take it you mean the second one: > > ht.c: printk(KERN_DEBUG "BA request denied - session is not " > ht.c: printk(KERN_DEBUG "BA request denied - queue unavailable for" > ht.c: printk(KERN_DEBUG "BA request denied - HW unavailable for" > > If so I find it strange as aggregation is disabled right now in > mac80211 -- see ieee80211_ht_agg_queue_add(). But keep in mind ath9k > ampdu_queues = 1 on ath9k right now and what I've seen so far is ath9k > sends frames on two tids during a session to an AP some initial data on > tid 0 and some data frames on tid 6. I think this a bug. Anyway you can > temporarilly fix this by increasing the number of ampdu_queues ath9k > declares. This whole ampdu_queues is bogus and just needs to be removed > to fix aggregation properly in mac80211. > >> Is that a known bug? Did i miss something in my setup? How to debug? > > For now please consider aggregation disabled and broken in mac80211 due > to two facts: > > 1. Its current design on relying ampdu_queue notion (tid_to_tx_q stuff). > 2. TX MQ changes require changes in order to deal with overwriting of > skb->cb upon having the skb enter the qdisc. > > Our initial work on aggregation addresses the second issue and we tried > to get it in for 2.6.27 as a temporary solution without having to rm -rf > ampdu_queue notion yet. This patch didn't make it upstream, however, due > to the more amount of changes required and some other hacks I saw on the > way. > > Its now time to simply fix aggregation properly by dealing with these > two issues. For now please consider aggregation disabled. > >> I will redo the very same test with an AR9160 minipci card as well. > > I suspect you will get similar results. But regardless the issues we > have to definitely address are your latency on ping/dhcp. Then we can > move on to throughput concerns but they may very well be related. > > Luis >
Thanks Luis, I must admit I do not fully understand your reply (I've not read the 802.11n specs .... ). I got the same results with AR9160. The exact error message is: BA request denied - queue unavailable for tid 0 BA request denied - queue unavailable for tid 6 BA request denied - queue unavailable for tid 7 However, this time, I got 27 Mbits, ie equivalent to 802.11g. Are there some patches I can try? Could you give me more details in order to fix aggregation? Regards, Benoit -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFI9kuDOR6EySwP7oIRArsdAKDTp1f+nK8zChNc+6ZeY+8qOhyFwACdGiEX 6vLnZb0y0GQav8QdgW9upVo= =XPku -----END PGP SIGNATURE----- _______________________________________________ ath9k-devel mailing list ath9k-devel@lists.ath9k.org https://lists.ath9k.org/mailman/listinfo/ath9k-devel