From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail.atheros.com ([12.19.149.2]:10046 "EHLO mail.atheros.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752167Ab1AGUW1 convert rfc822-to-8bit (ORCPT ); Fri, 7 Jan 2011 15:22:27 -0500 Received: from mail.atheros.com ([10.10.20.108]) by sidewinder.atheros.com for ; Fri, 07 Jan 2011 12:22:09 -0800 Date: Fri, 7 Jan 2011 12:22:24 -0800 From: "Luis R. Rodriguez" To: Aleksandar Milivojevic CC: Helmut Schaa , Luis Rodriguez , "linux-wireless@vger.kernel.org" , Wolfgang Kufner , Luis Correia , "users@rt2x00.serialmonkey.com" Subject: Re: [rt2x00-users] Linksys WUSB600N v1 disconnecting from AP Message-ID: <20110107202224.GI21588@tux> References: <20110107024432.GC20431@tux> <201101071111.17423.helmut.schaa@googlemail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" In-Reply-To: Sender: linux-wireless-owner@vger.kernel.org List-ID: On Fri, Jan 07, 2011 at 11:46:48AM -0800, Aleksandar Milivojevic wrote: > On Fri, Jan 7, 2011 at 2:11 AM, Helmut Schaa > wrote: > > Am Freitag, 7. Januar 2011 schrieb Luis R. Rodriguez: > >> On Thu, Jan 06, 2011 at 08:31:22AM -0800, Aleksandar Milivojevic wrote: > >> > Playing with it a bit more this morning.  Looks like the connection > >> > from wireless adapter to my AP drops periodically.  Sometimes it > >> > recovers (sometimes after several attempts), sometimes it does not. > >> > Seems to be very random: > >> > > >> > # egrep 'authent|associat' /var/log/debug > >> > Jan  6 08:00:54 toporko kernel: [   47.570810] wlan0: authenticate > >> > with 00:1e:52:79:e9:ff (try 1) > >> > Jan  6 08:00:54 toporko kernel: [   47.571321] wlan0: authenticated > >> > Jan  6 08:00:56 toporko kernel: [   49.174175] wlan0: associate with > >> > 00:1e:52:79:e9:ff (try 1) > >> > Jan  6 08:00:56 toporko kernel: [   49.175536] wlan0: associated > >> > Jan  6 08:06:01 toporko kernel: [  354.230874] wlan0: authenticate > >> > with 00:1e:52:79:e9:ff (try 1) > >> > Jan  6 08:06:01 toporko kernel: [  354.231364] wlan0: authenticated > >> > Jan  6 08:06:01 toporko kernel: [  354.236066] wlan0: associate with > >> > 00:1e:52:79:e9:ff (try 1) > >> > Jan  6 08:06:01 toporko kernel: [  354.236865] wlan0: associated > >> > Jan  6 08:09:36 toporko kernel: [  569.868923] wlan0: authenticate > >> > with 00:1e:52:79:e9:ff (try 1) > >> > Jan  6 08:09:36 toporko kernel: [  569.869416] wlan0: authenticated > >> > Jan  6 08:09:36 toporko kernel: [  569.873736] wlan0: associate with > >> > 00:1e:52:79:e9:ff (try 1) > >> > Jan  6 08:09:36 toporko kernel: [  569.874507] wlan0: associated > >> > Jan  6 08:09:46 toporko kernel: [  579.233563] wlan0: authenticate > >> > with 00:1e:52:79:e9:ff (try 1) > >> > Jan  6 08:09:46 toporko kernel: [  579.235574] wlan0: authenticated > >> > Jan  6 08:09:46 toporko kernel: [  579.240737] wlan0: associate with > >> > 00:1e:52:79:e9:ff (try 1) > >> > Jan  6 08:09:46 toporko kernel: [  579.241518] wlan0: associated > >> > Jan  6 08:09:57 toporko kernel: [  590.830933] wlan0: authenticate > >> > with 00:1e:52:79:e9:ff (try 1) > >> > Jan  6 08:09:57 toporko kernel: [  590.831435] wlan0: authenticated > >> > Jan  6 08:09:57 toporko kernel: [  590.839102] wlan0: associate with > >> > 00:1e:52:79:e9:ff (try 1) > >> > Jan  6 08:09:57 toporko kernel: [  590.839881] wlan0: associated > >> > Jan  6 08:21:29 toporko kernel: [ 1282.823289] wlan0: authenticate > >> > with 00:1e:52:79:e9:ff (try 1) > >> > Jan  6 08:21:29 toporko kernel: [ 1282.823783] wlan0: authenticated > >> > Jan  6 08:21:29 toporko kernel: [ 1282.828990] wlan0: associate with > >> > 00:1e:52:79:e9:ff (try 1) > >> > Jan  6 08:21:29 toporko kernel: [ 1282.830132] wlan0: associated > >> > Jan  6 08:25:30 toporko kernel: [ 1523.433931] wlan0: authenticate > >> > with 00:1e:52:79:e9:ff (try 1) > >> > Jan  6 08:25:30 toporko kernel: [ 1523.434930] wlan0: authenticated > >> > Jan  6 08:25:30 toporko kernel: [ 1523.439868] wlan0: associate with > >> > 00:1e:52:79:e9:ff (try 1) > >> > Jan  6 08:25:30 toporko kernel: [ 1523.440652] wlan0: associated > >> > > >> > So far, it managed to re-connect every time.  Though, I'm rather sure > >> > if I leave it long enough, the last night's case of connection dropped > >> > completely would repeat sooner or later (even last night, there were > >> > some connect/disconnect events before connection was dropped > >> > permanently). > >> > > >> > The AP reports signal from wireless card between -70 and -75dB, noise > >> > at -96dB, and speed at 120mbps (with occasional drop to 45mbps). > >> > These numbers sound about OK for the location (on the other side of my > >> > apartment, few walls in between).  For comparison, if I position my > >> > MacBook at same location (right next to my Linux box), AP reports > >> > signal from its AirPort card at about -60dB and speed in about 100mbps > >> > range and no drops. > >> > >> The Linux regulatory code only relies on the Country IE from the AP you > >> decide to associate to, that's it. Then, as for all the regulatory stuff > >> popping out once you are associated, its happening because as I see it > >> you are being disconnected from the AP. The Linux regulatory code will > >> reset the regulatory settings after you disconnect from an AP. > >> > >> The disconnect issues should not be regularory related from what I see. > >> Seems like a general disconnect issue with your driver. > > > > Sounds reasonable. Thanks for the update Luis. So, it's more likely a > > rt2x00 or mac80211 issue. > > I'd put my vote there too, probably hitting some corner case or > something specific to either WUSB600N or Airport Extreme or > combination of the two. I'd be glad to help debug the issue, and if > you need any info just give me a shout what to do, what to try out, > and/or what to look for. > > There was huge improvement in rt2x00 regarding support for Linksys > WUSB600N over the last half a year or so. Until several months ago, > using rt2x00 driver, I wasn't able to connect to my AP at all (I would > see the list of networks, but would not be able to connect to any of > them). The version from 2.6.35 kernel would connect for short period > of time, but speed was abysmal (in order of few kB/sec), and > connection would be completely dropped within minutes. With the > latest version of driver (compiled from comapt-wireless tarball), I'm > getting good transfer speeds, and connection to my AP is mostly up > (there's some flapping every few minutes, as you can see from logs). > In the last two days, there was only one occurrence where connection > to my AP was dropped and driver failed to re-connect. You may want to try checing the 'iw event -t' output while the issue happens. Maybe it is due to a roaming issue, if you are using a large BSS and roam in between you may want to try using wpa_supplicant with nl80211 and use the new bgscan module from wpa_supplicant to trigger you to only switch based on triggered events from nl80211 like signal rssi changes. Here is an example supplicant conf that uses the bgscan module: # WPA-PSK/TKIP ctrl_interface=/var/run/wpa_supplicant network={ ssid="my-corp-cool-bss" bgscan="simple:30:-45:300" key_mgmt=WPA-PSK proto=RSN pairwise=CCMP group=CCMP psk="foobar_is_great" } No Linux distributions today uses this other than ChromeOS, but they should all change to use it. Luis