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Changes between Version 9 and Version 10 of StuckBeacon

Author:
p0g0 (IP: 0.0.0.0)
Timestamp:
02/03/06 13:51:18 (14 years ago)
Comment:

added the athdebug calls to help sort out SBP's, ass't formatting

Legend:

Unmodified
Added
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Modified
  • StuckBeacon

    v9 v10  
    55The Stuck Beacon Problem (SBP) is an intermittant but severe problem for some users.  It has been around for a while, but has yet to be resolved.  Please help collect and report data on this bug by suffixing your experience to this page.  Since no one yet knows the basis for the problem, the meaures to report here will be refined over time.  Please read on for more hints. 
    66 
     7To enable debug messages to help sort out the stuck beacon problem:  
     8 athdebug +beacon +beacon_proc +fatal  
    79 
    8 The SBP is generally associated with a reduction in performance.  Data transfer rates drop.  Data may stop moving all together.  You may get a 'Stuck Beacon' message. 
     10 80211debug +assoc +elemid 
    911 
    10 Anecdotal evidence suggests that the SBP occurs to varying degrees, and only the most severe are reported as 'Stuck Beacon'.   
     12The SBP is strictly an issue on AP's, stations don't have the Problem. The SBP is generally associated with a reduction in performance.  Data transfer rates drop.  Data may stop moving all together.  You may get a 'Stuck Beacon' message.  
     13 
     14Anecdotal evidence suggests that the SBP occurs to varying degrees, and only the most severe are reported as 'Stuck Beacon'.  Some SBP's yield an simple error, but panics have been reported. 
    1115 
    1216One of the measures that can indicate the problem is an ''acceleration'' in the card's hardware interrupt rate.  To watch the accumulation of interrupts on '''wifi0''', key in the folowing line from a console.  Substitute your interface name for '''wifi0''':  in the 'old' code, typically that is '''ath0''', and in the 'NG' code, the name of the base device, typically '''wifi0'''.  If the accumulation rate accelerates significantly, you may be heading towards a stuck beacon.  NB:  the count shown below will increase, and that is normal.  Accelerated rates are the issue. 
    1418 watch -n 1 'cat /proc/interrupts | grep wifi0' 
    1519 
     20Stuck Beacons can often be the result of a mis-installation or mis-configuration. It's been reported that changing settings stopped the stuck beacon (which settings you ask:  the reporter said "I don't remember which setting stopped that").   
    1621 
    17 I encounter the SBP mostly when doing things that are network-intensive- RDesktop and VNC especially seem to trigger the problem. It does seem interrupt-related- I was watching a video recorded with MythTV today when it happened, and the video became choppy, though CPU idle was still over 90%. If I down the interface and rmmod ath_pci, that sometimes helps, but not always. Today, I encoutered the SBP, downed the interface, removed the driver, re-inserted it, brought the interface back up, and was able to work for another two hours. But after that, the SBP persisted through several down-remove-modprobe-up cycles, and I ended up going back to wired.  
     22Another reporter using a D-link DWL-AG650 PCI card with drivers from CVS on 12/28/2005 encountered the SBP mostly when doing things that are network-intensive- RDesktop and VNC especially seem to trigger the problem. Watching a video recorded with MythTV induced the SBC and the video became choppy, though CPU idle was still over 90%. Downing the interface and rmmod ath_pci, sometimes helps, but not always,  ie:  got the SBP, downed the interface, removed the driver, re-inserted it, brought the interface back up, and that worked for another two hours. But after that, the SBP persisted through several down-remove-modprobe-up cycles.   
    1823 
    19 I should mention I'm using a D-link DWL-AG650 PCI card with drivers from CVS on 12/28/2005 in master mode as my access point, and an Atheros AR5001X Mini-PCI card in my laptop with drivers from 9/21/2005 as a client. I've only ever seen the SBP on my access point, never the laptop. 
    20  
    21 Perhaps someone could post debugging procedures, and where to send debug data to on this page?  
    22  
    23  
    24 it appears that stuck beacon can be caused mostly by wireless cards that have some sort of power saving feature, namely intel centrino (2200BG ) and equiv  cards. this causes stuck beacon to appear, to fix this, turn the card out of power saving mode in the control panel, this may or may not fix the problem, but appeared to work for me. uptime is around 10+days with latest madwifi drivers. 
    25  
    26 more information specific to intel centrino laptops can be found here: http://support.intel.com/support/wireless/wlan/sb/cs-006205.htm 
     24It appears that stuck beacon can be caused by wireless cards that have some sort of power saving feature, namely intel centrino (2200BG ) and equiv  cards.  To fix this, turn the card out of power saving mode in the control panel, this may or may not fix the problem, but appeared to work for me. Uptime is around 10+days with latest madwifi drivers. More information specific to intel centrino laptops can be found here: http://support.intel.com/support/wireless/wlan/sb/cs-006205.htm 
    2725 
    2826Here is a little perl script giving you the differences. Usage: store the code in a file, e.g. "madwifi.pl". Call it with  
    5250} 
    5351}}} 
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