mac80211: correct wext transmit power handler
Wext makes no assumptions about the contents of
data->txpower.fixed and data->txpower.value when
data->txpower.disabled is set, so do not update
the user-requested power level while disabling.
Also, when wext configures a really _fixed_ power
output [1], we should reject it instead of limiting it
to the regulatory constraint. If the user wants to set
a _limit_ [2] then we should honour that.
[1] iwconfig wlan0 txpower 20dBm fixed
[2] iwconfig wlan0 txpower 10dBm
This fixes
http://www.intellinuxwireless.org/bugzilla/show_bug.cgi?id=1942
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index a6f1d8a..fbcbed6 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -258,7 +258,7 @@
(chan->max_power - local->power_constr_level) :
chan->max_power;
- if (local->user_power_level)
+ if (local->user_power_level >= 0)
power = min(power, local->user_power_level);
if (local->hw.conf.power_level != power) {
diff --git a/net/mac80211/wext.c b/net/mac80211/wext.c
index deb4ece..ce9115c 100644
--- a/net/mac80211/wext.c
+++ b/net/mac80211/wext.c
@@ -417,6 +417,7 @@
{
struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
struct ieee80211_channel* chan = local->hw.conf.channel;
+ bool reconf = false;
u32 reconf_flags = 0;
int new_power_level;
@@ -427,14 +428,38 @@
if (!chan)
return -EINVAL;
- if (data->txpower.fixed)
- new_power_level = min(data->txpower.value, chan->max_power);
- else /* Automatic power level setting */
- new_power_level = chan->max_power;
+ /* only change when not disabling */
+ if (!data->txpower.disabled) {
+ if (data->txpower.fixed) {
+ if (data->txpower.value < 0)
+ return -EINVAL;
+ new_power_level = data->txpower.value;
+ /*
+ * Debatable, but we cannot do a fixed power
+ * level above the regulatory constraint.
+ * Use "iwconfig wlan0 txpower 15dBm" instead.
+ */
+ if (new_power_level > chan->max_power)
+ return -EINVAL;
+ } else {
+ /*
+ * Automatic power level setting, max being the value
+ * passed in from userland.
+ */
+ if (data->txpower.value < 0)
+ new_power_level = -1;
+ else
+ new_power_level = data->txpower.value;
+ }
- local->user_power_level = new_power_level;
- if (local->hw.conf.power_level != new_power_level)
- reconf_flags |= IEEE80211_CONF_CHANGE_POWER;
+ reconf = true;
+
+ /*
+ * ieee80211_hw_config() will limit to the channel's
+ * max power and possibly power constraint from AP.
+ */
+ local->user_power_level = new_power_level;
+ }
if (local->hw.conf.radio_enabled != !(data->txpower.disabled)) {
local->hw.conf.radio_enabled = !(data->txpower.disabled);
@@ -442,7 +467,7 @@
ieee80211_led_radio(local, local->hw.conf.radio_enabled);
}
- if (reconf_flags)
+ if (reconf || reconf_flags)
ieee80211_hw_config(local, reconf_flags);
return 0;