Date: Fri, 2 Jul 2010 16:38:12 GMT From: Adrian Chadd <adrian@FreeBSD.org> To: FreeBSD-gnats-submit@FreeBSD.org Subject: kern/148322: Triggering atheros wifi beacon misses in hostap mode under no radio traffic load Message-ID: <201007021638.o62GcCsk068928@freefall.freebsd.org> Resent-Message-ID: <201007021640.o62Ge5Lo068957@freefall.freebsd.org>
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>Number: 148322 >Category: kern >Synopsis: Triggering atheros wifi beacon misses in hostap mode under no radio traffic load >Confidential: no >Severity: non-critical >Priority: low >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Fri Jul 02 16:40:04 UTC 2010 >Closed-Date: >Last-Modified: >Originator: Adrian Chadd >Release: FreeBSD wap1 9.0-CURRENT >Organization: >Environment: * ubiquiti routerstation pro * ubiquiti SR-2 card, AR5213A based * running -current from local USB hard disk FreeBSD wap1 9.0-CURRENT FreeBSD 9.0-CURRENT #5: Fri Jul 2 23:33:56 WST 2010 adrian@pcbsd-3114:/data/freebsd/mips/head/obj-mip s/mips.mips/data/freebsd/mips/head/src/sys/AR71XX mips >Description: Reproducing "missed x consecutive beacon" debug messages by doing SPI flash IO. This isn't -necessarily- a radio stability/signal strength issue (but I'll re-test that comment when I acquire something spectrum analyzer-y) but it could indicate some other problem. The flash IO is through the AR71XX SPI bus. It shouldn't interfere with the beacon transmission, right? >How-To-Repeat: * setup interface in hostap mode: rc.conf: wlans_ath0="wlan0" create_args_wlan0="wlanmode hostap mode 11g country AU txpower 2 bgscan" ifconfig_wlan0="ssid cacheboy_test_1 mode 11g channel 6 txpower 2 up" * create hostapd config to make sure neighbors don't steal wifi: interface=wlan0 driver=bsd ssid=cacheboy_test_1 wpa=3 wpa_key_mgmt=WPA-PSK wpa_passphrase=XXXX wpa_pairwise=CCMP TKIP * create bridge group just for testing normal traffic: rc.conf: cloned_interfaces="bridge0" ifconfig_bridge0="addm wlan0 stp wlan0 addm wlan1 stp wlan1 addm arge0 stp arge0 up" * enable beacon debug messages (assuming the kernel has been compiled with atheros debugging): # sysctl dev.ath.0.debug=0x80 * dd from flash: wap1# dd if=/dev/redboot/kernel of=/dev/null bs=64k ath0: ath_beacon_proc: missed 1 consecutive beacons ath0: ath_beacon_proc: resume beacon xmit after 1 misses ath0: ath_beacon_proc: missed 1 consecutive beacons ath0: ath_beacon_proc: resume beacon xmit after 1 misses <etc, etc> >Fix: Weirdly enough, tweaking the HAL DMA/software beacon timings quieten those messages: # sysctl hw.ath.hal.dma_brt=1000 # sysctl hw.ath.hal.sw_brt=3000 # ifconfig wlan0 down #ifconfig wlan0 up # dd if=/dev/redboot/kernel of=/dev/null bs=64k I haven't tried passing any traffic through the AP yet with these HAL settings. 100/300 also works. Dropping it back to the default of 2/10 sees the missed beacon messages. >Release-Note: >Audit-Trail: >Unformatted:
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