Thanks Emmanuel Yes. The problem here seems to be the same as you saw. There is no ping packet loss when I use AC==BK. Would you please point me to the code, e.g file/function, etc I would like to fix this problem (if I can). Thanks again -----Original Message----- From: Emmanuel Grumbach [mailto:egrumbach@xxxxxxxxx] Sent: Tuesday, June 21, 2011 4:11 PM To: Chaoxing Lin Cc: Ben Greear; ath9k-devel@xxxxxxxxxxxxxxx; linux-wireless@xxxxxxxxxxxxxxx Subject: Re: Help on AMPDU stuck in transmit queue On Tue, Jun 21, 2011 at 19:16, Chaoxing Lin <Chaoxing.Lin@xxxxxxxxxxxxxx> wrote: > > Anybody,any ideas/comments? > > Here is my update. > > I tried 2.6.39.1. The situation gets better, but not fixed completely. The ping packets still lose (about 62 seconds) once a while. > I say "gets better" because it recovers. > > The ping session recovers after about 62 seconds which matches to 2 NULL data packet interval. I sniffed the air, it looks like every 31 seconds, a NULL data packet is sent out from client. > > > Again, the symptom does not happen when 802.11n is disabled on AP. > > Can anyone explain or help? > > Below is my ping session info (message on console) > Can you please try to send the pings with AC != BE. I saw once a bug related to ampdu reordering buffer. NULL packets would enter the reordering buffer and mess up the counters there. Since the reordering buffer is tid-wise, trying with another AC may help to understand. I assume that QoS NULL data packets are sent as BE. The fact that the ping recovers after a while may be explained by the wrap around of the sequence. This is a really wild guess... but sometimes it can hit.... -- 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
