Michael Wu wrote:
On Sunday 08 April 2007 01:04, Larry Finger wrote:
In mac80211 the 'qual' and 'level' values are interchanged. The patch also
places the 'qual' value on a 0 - 100 scale and calculated using the formula
contained in iwlib.
NACK. Qual (arbitrary signal quality) and level (RSSI) values are correct and
userspace is responsible for scaling any statistics values.
I disagree. For the wireless extensions output, the maximum values are set implicitly in the
iw_range struct. In addition, the level is always in dBm (a negative number), whereas the RSSI is an
arbitrary positive number. Because the maximum value is driver dependent, it must be specified when
the driver initializes the MAC layer.
In any case, the current code is broken. Without my patch, an iwconfig command with bcm43xx-mac80211
produces the line:
Link Quality=216/146 Signal level=-197 dBm Noise level=-63 dBm
We could argue about the Link Quality, although the x/146 looks pretty strange. The Signal level of
-197 dBm is impossible. With my patch, the same version of bcm43xx gets the line
Link Quality=90/100 Signal level=-36 dBm Noise level=-69 dBm
That Signal level matches what comes from both bcm43xx-softmac and the Windows driver running under
ndiswrapper.
Larry
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