From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wang Jian Date: Tue, 03 Mar 2009 02:30:17 +0800 Subject: [ath9k-devel] Ath9k packets dropping issue Message-ID: <49AC25B9.5030604@linux.net.cn> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ath9k-devel@lists.ath9k.org Hi there, I am using openwrt on TL-WR941ND, using dev snapshot build ( http://downloads.openwrt.org/people/agb/ar71xx-ath9k-snapshots/ ). root at OpenWrt:~# uname -a Linux OpenWrt 2.6.28.7 #2 Sat Feb 28 23:35:50 PST 2009 mips unknown TL-WR941ND is an consumer router based on AP81, using AR9132/AR9103 chips (per RoundSparrow). I notice strange packets dropping, for example, I can (telnet) connect from wireless client to the other side of (wired) network to port 22, but got stuck when connection established. After random but long freezing time, I get ssh banner. But ping from wireless client to the other side of (wired) network is very smooth. The scenario: A(XP box) .......(wireless)...... B (WR941N as pure AP) ------------(wired)------------ C(Linux box) 192.168.0.121 192.168.1.1 192.168.0.254 1. A ping C: very smooth 2. C ping A: most ping lost, with one or two responses out of 40+ pings I silent A by closing most packet sending program, run sniffers (wireshark or tcpdump) on A,B,C, and watch tx/rx counters of B's wlan0 interface. Then I run ping from A to C, and C to A. 1. For every ping packets A sends to C, B's rx and tx counter increase. 2. For nearly every ping packets C sends to A, B's tx counter increases, A doesn't receive this ping, B's rx counter stays unchanged. 3. Every a few seconds, arp requests occurs, and C may get one and only one ping response. 4. All ping request shows itself in B's tcpdump output. So, things get clear here: B seems only succeed to do tx after rx on wireless interface. This looks like queue related problem or interrupt handler problem.