This patch uses power constraint level while determining the maximum
transmit power, there by it makes sure that any power mitigation
requirement for the channel in the current regulatory domain is met.
Signed-off-by: Vasanthakumar Thiagarajan <[email protected]>
---
include/net/mac80211.h | 2 ++
net/mac80211/ieee80211_i.h | 3 +++
net/mac80211/main.c | 10 ++++++++--
net/mac80211/mlme.c | 9 +++++++++
net/mac80211/spectmgmt.c | 21 +++++++++++++++++++++
5 files changed, 43 insertions(+), 2 deletions(-)
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 153a8d1..a1126d3 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -549,6 +549,7 @@ enum ieee80211_conf_changed {
* @flags: configuration flags defined above
* @power_level: requested transmit power (in dBm)
* @user_power_level: User configured transmit power (in dBm)
+ * @power_constr_level: Power constraint level advertised in 11h beacon (in dBm)
* @channel: the channel to tune to
* @ht: the HT configuration for the device
* @long_frame_max_tx_count: Maximum number of transmissions for a "long" frame
@@ -563,6 +564,7 @@ struct ieee80211_conf {
u32 flags;
int power_level;
int user_power_level;
+ int power_constr_level;
u16 listen_interval;
bool radio_enabled;
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 117718b..1abe96e 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -964,6 +964,9 @@ void ieee80211_process_addba_request(struct ieee80211_local *local,
void ieee80211_process_measurement_req(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt,
size_t len);
+void ieee80211_handle_pwr_constr(struct ieee80211_sub_if_data *sdata,
+ u16 capab_info, u8 *pwr_constr_elem,
+ u8 pwr_constr_elem_len);
/* utility functions/constants */
extern void *mac80211_wiphy_privid; /* for wiphy privid */
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 8831e87..66108f6 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -224,10 +224,16 @@ int ieee80211_hw_config(struct ieee80211_local *local, u32 changed)
changed |= IEEE80211_CONF_CHANGE_CHANNEL;
}
- if (!local->hw.conf.user_power_level)
+ if (local->sw_scanning)
power = chan->max_power;
else
- power = min(chan->max_power, local->hw.conf.user_power_level);
+ power = local->hw.conf.power_constr_level ?
+ (chan->max_power - local->hw.conf.power_constr_level) :
+ chan->max_power;
+
+ if (local->hw.conf.user_power_level)
+ power = min(power, local->hw.conf.user_power_level);
+
if (local->hw.conf.power_level != power) {
changed |= IEEE80211_CONF_CHANGE_POWER;
local->hw.conf.power_level = power;
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index e317c6d..0292955 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -911,6 +911,8 @@ static void ieee80211_set_disassoc(struct ieee80211_sub_if_data *sdata,
local->oper_channel_type = NL80211_CHAN_NO_HT;
config_changed |= IEEE80211_CONF_CHANGE_HT;
+ local->hw.conf.power_constr_level = 0;
+
del_timer_sync(&local->dynamic_ps_timer);
cancel_work_sync(&local->dynamic_ps_enable_work);
@@ -1839,6 +1841,13 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
* for the BSSID we are associated to */
regulatory_hint_11d(local->hw.wiphy,
elems.country_elem, elems.country_elem_len);
+
+ /* TODO: IBSS also needs this */
+ if (elems.pwr_constr_elem)
+ ieee80211_handle_pwr_constr(sdata,
+ le16_to_cpu(mgmt->u.probe_resp.capab_info),
+ elems.pwr_constr_elem,
+ elems.pwr_constr_elem_len);
}
ieee80211_bss_info_change_notify(sdata, changed);
diff --git a/net/mac80211/spectmgmt.c b/net/mac80211/spectmgmt.c
index f72bad6..f4b72d7 100644
--- a/net/mac80211/spectmgmt.c
+++ b/net/mac80211/spectmgmt.c
@@ -84,3 +84,24 @@ void ieee80211_process_measurement_req(struct ieee80211_sub_if_data *sdata,
mgmt->sa, mgmt->bssid,
mgmt->u.action.u.measurement.dialog_token);
}
+
+void ieee80211_handle_pwr_constr(struct ieee80211_sub_if_data *sdata,
+ u16 capab_info, u8 *pwr_constr_elem,
+ u8 pwr_constr_elem_len)
+{
+ struct ieee80211_conf *conf = &sdata->local->hw.conf;
+
+ if (!(capab_info & WLAN_CAPABILITY_SPECTRUM_MGMT))
+ return;
+
+ /* Power constraint IE length should be 1 octet */
+ if (pwr_constr_elem_len != 1)
+ return;
+
+ if ((*pwr_constr_elem <= conf->channel->max_power) &&
+ (*pwr_constr_elem != conf->power_constr_level)) {
+ conf->power_constr_level = *pwr_constr_elem;
+ ieee80211_hw_config(sdata->local, 0);
+ }
+}
+
--
1.5.5.1
On Mon, 2009-01-05 at 15:06 +0530, Vasanthakumar Thiagarajan wrote:
> - if (!local->hw.conf.user_power_level)
> + if (local->sw_scanning)
> power = chan->max_power;
> else
> - power = min(chan->max_power, local->hw.conf.user_power_level);
> + power = local->hw.conf.power_constr_level ?
> + (chan->max_power - local->hw.conf.power_constr_level) :
> + chan->max_power;
I think I'd prefer that to be written as
if (!scanning && power_constr_level)
power = ... - ...
else
power = chan->max_power;
Also, I don't understand the subtraction? And why are you checking only
for sw scanning and not hw scanning?
> +void ieee80211_handle_pwr_constr(struct ieee80211_sub_if_data *sdata,
> + u16 capab_info, u8 *pwr_constr_elem,
> + u8 pwr_constr_elem_len)
> +{
> + struct ieee80211_conf *conf = &sdata->local->hw.conf;
> +
> + if (!(capab_info & WLAN_CAPABILITY_SPECTRUM_MGMT))
> + return;
> +
> + /* Power constraint IE length should be 1 octet */
> + if (pwr_constr_elem_len != 1)
> + return;
> +
> + if ((*pwr_constr_elem <= conf->channel->max_power) &&
> + (*pwr_constr_elem != conf->power_constr_level)) {
> + conf->power_constr_level = *pwr_constr_elem;
> + ieee80211_hw_config(sdata->local, 0);
That needs a changed flag, no? And how does the subtraction make sense
like this? The spec talks about the country element's max power, and
then subtracting this, to get the local power, but if the local power
was set lower than that then we shouldn't subtract even more, no?
johannes
Oops, i mistakenly sent as attachment, please see my comments below.
On Mon, Jan 05, 2009 at 04:42:34PM +0530, Johannes Berg wrote:
>
> I think I'd prefer that to be written as
>
> if (!scanning && power_constr_level)
> power = ... - ...
> else
> power = chan->max_power;
>
> Also, I don't understand the subtraction? And why are you checking
> only
> for sw scanning and not hw scanning?
I think driver should handle in case of hw_scanning.
> > +
> > + if ((*pwr_constr_elem <= conf->channel->max_power) &&
> > + (*pwr_constr_elem != conf->power_constr_level)) {
> > + conf->power_constr_level = *pwr_constr_elem;
> > + ieee80211_hw_config(sdata->local, 0);
>
> That needs a changed flag, no?
No, ieee80211_hw_config() will take care.
>And how does the subtraction make sense
> like this? The spec talks about the country element's max power,
> and
> then subtracting this, to get the local power, but if the local
> power
> was set lower than that then we shouldn't subtract even more, no?
This is more concervative way of processing power constraint. Yeah,
you are correct
that we might be setting lower tx power than the allowed one when we
subtract power
constraint from already min power (of reg data base and 11d ie)
instead of only power
limit advertised in 11d ie, but this situation is uncommon.
Vasanth
On Mon, 2009-01-05 at 19:07 +0530, Vasanthakumar Thiagarajan wrote:
[an email that somehow was just an attachment?]
> > Also, I don't understand the subtraction? And why are you checking only
> > for sw scanning and not hw scanning?
>
> I think driver should handle in case of hw_scanning.
Yes, true, it's all per-channel too.
> > > +
> > > + if ((*pwr_constr_elem <= conf->channel->max_power) &&
> > > + (*pwr_constr_elem != conf->power_constr_level)) {
> > > + conf->power_constr_level = *pwr_constr_elem;
> > > + ieee80211_hw_config(sdata->local, 0);
> >
> > That needs a changed flag, no?
>
> No, ieee80211_hw_config() will take care.
Indeed, my mistake.
> > And how does the subtraction make sense
> > like this? The spec talks about the country element's max power, and
> > then subtracting this, to get the local power, but if the local power
> > was set lower than that then we shouldn't subtract even more, no?
>
>
> This is more concervative way of processing power constraint. Yeah, you are correct
> that we might be setting lower tx power than the allowed one when we subtract power
> constraint from already min power (of reg data base and 11d ie) instead of only power
> limit advertised in 11d ie, but this situation is uncommon.
Ok, makes sense, let's not worry about it then.
That means the unmodified patch is fine, I guess.
johannes