From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Ehrmann Date: Sun, 21 Nov 2010 19:38:09 -0800 Subject: [ath9k-devel] TX packets dropped In-Reply-To: References: <4CE8C56D.6080609@gmail.com> Message-ID: <4CE9E5A1.7090306@gmail.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ath9k-devel@lists.ath9k.org On 11/21/2010 4:51 PM, Brian Prodoehl wrote: > On Sun, Nov 21, 2010 at 2:08 AM, David Ehrmann wrote: >> I have an AR9220 mini PCI card (Sparklan WMIA-198n) on an Alix 3d2 board >> running OpenWrt (2.6.32.25 kernel). I set up the radio in AP mode, give >> it encryption, then connected with another computer with an Intel >> 802.11n card. The connection wasn't reliable, so I tested it with >> iperf. When the client sends packets, they almost all make it, but when >> the AP sends them, no more than 66% make it. I'm trying to figure out >> what the problem could be. It shouldn't be interference--this is in a >> 5ghz band, and RX was fine. It could be a bad pigtail or antenna, but >> I'm not sure how I can test for that. It might be the motherboard's >> power supply, so I'm looking into how many watts it can supply (the card >> specs say it takes ~2.5 watts). I tried forcing 802.11g mode, and the >> issue was still there, and I dropped TX power, but it didn't seem to >> affect anything. >> >> Any ideas? Is there a way to check stats on each antenna? > What do ping times look like between AP and client? I'm seeing > similar behavior with OpenWrt trunk (r24043) and an AP with an AR9160 > chip. I'm having TX traffic queue up on the AP for seconds at a time, > so I'll have periods of no traffic at all, and then all the pings will > come through at once, with times of 8s, 7s, 6s, 5s, 4s, 3s, 2s, 1s, > and 1.97ms or whatever. I have two other APs here with different > drivers and chipsets that don't exhibit this. I don't remember seeing > this with recent builds of backfire, so maybe its a relatively recent > regression in OpenWrt. You're running trunk, right? What svn rev? My ping times are typically between 2ms and 5ms, but around 1 in 15 is more like 15ms to 50ms. My 802.11g AP behaves roughly the same. Traffic could be bunching up, though. Sometimes the console (over SSH) won't respond when I hit enter, but a few seconds later, all the new lines show up. I'm using r23987, so it might be the same issue.