[collectd-changes] collectd, the system statistics collection daemon: Changes to 'collectd-4.3'

[Florian Forster]

 src/wireless.c |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)

New commits:
commit e8c6efb8bf77e835c28ff2c14f13aecbb73e3e28
Author: JoW <xm at leipzig.freifunk.net>
Date:   Mon Jun 9 13:27:16 2008 +0200

    wireless plugins: Interpret noise/power values >100 as (dBm + 256).
    
    Hi list,
    
    I currently develop an embedded statistics application and web interface
    for OpenWrt Kamikaze based on Collectd and RRDTool.
    
    While working with the wireless plugin I noticed some incompatibilities
    with different drivers, namely the Broadcom proprietary driver and madwifi.
    
      /proc/net/wireless on Broadcom:
    
       Inter-| sta-|   Quality        |   Discarded packets               | Missed | WE
        face | tus | link level noise |  nwid  crypt   frag  retry   misc | beacon | 18
          wl0: 0000    2.  179.  163.       0      0   8040    723      0        0
    
      With the Broadcom proprietary driver you get the actual signal and noise
      dbm units by substracting 255 from the values in /proc:
    
       level: 179 - 255 = -76 dBm
       noise: 163 - 255 = -92 dBm
    
      /proc/net/wireless on Atheros SoC:
    
       Inter-| sta-|   Quality        |   Discarded packets               | Missed | WE
        face | tus | link level noise |  nwid  crypt   frag  retry   misc | beacon | 22
         ath0: 0004   21.  -73.  -94.   21841      0      0      0      0        0
    
      Madwifi writes the actual dBm values into /proc.
    
    So we have (at least for now) three possible types of values:
    
       ( x > 0.0   && x <= 100.0 )	current implementation: x is in percent (?)
    
       ( x > 100.0 && x <= 255.0 )	broadcom: range intersects with percents but
    				values below 100.0 (100.0 - 255.0 = -155.0 dBm)
    				are somewhat unlikely to occur
    
       ( x < 0.0 )			atheros: value is already in dBm
    
    A patch which implements the two additional possibilities in collectd's wireless
    plugin can be found in the OpenWrt Trac:
    
    https://dev.openwrt.org/browser/packages/utils/collectd/patches/200-wireless-compat.patch
    
    The patch was made against v4.4.0 of collectd but should work with v4.4.1 too.
    It would be nice to have this in the next release or so :)
    
    Greetings,
    JoW