forge/linux-pinenote
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

cfg80211/mac80211: use reduced txpower for 5 and 10 MHz

Browse source 
Some regulations (like germany, but also FCC) express their transmission
power limit in dBm/MHz or mW/MHz. To cope with that and be on the safe
side, reduce the maximum power to half (10 MHz) or quarter (5 MHz)
when operating on these reduced bandwidth channels.

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
This commit is contained in:
Simon Wunderlich 2013-07-08 16:55:55 +02:00 • committed by Johannes Berg
commit 0430c88347
4 changed files with 31 additions and 3 deletions
Download patch file Download diff file Expand all files Collapse all files

27
include/net/cfg80211.h
View file

@ -460,6 +460,33 @@ ieee80211_chandef_rate_flags(struct cfg80211_chan_def *chandef)
return 0;
}
/**
* ieee80211_chandef_max_power - maximum transmission power for the chandef
*
* In some regulations, the transmit power may depend on the configured channel
* bandwidth which may be defined as dBm/MHz. This function returns the actual
* max_power for non-standard (20 MHz) channels.
*
* @chandef: channel definition for the channel
*
* Returns: maximum allowed transmission power in dBm for the chandef
*/
static inline int
ieee80211_chandef_max_power(struct cfg80211_chan_def *chandef)
{
switch (chandef->width) {
case NL80211_CHAN_WIDTH_5:
return min(chandef->chan->max_reg_power - 6,
chandef->chan->max_power);
case NL80211_CHAN_WIDTH_10:
return min(chandef->chan->max_reg_power - 3,
chandef->chan->max_power);
default:
break;
}
return chandef->chan->max_power;
}
/**
* enum survey_info_flags - survey information flags
*