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-rw-r--r--include/net/mac80211.h12
-rw-r--r--net/mac80211/scan.c64
2 files changed, 69 insertions, 7 deletions
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index daa539a..174dc1d 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -1307,11 +1307,13 @@ enum ieee80211_ampdu_mlme_action {
*
* @hw_scan: Ask the hardware to service the scan request, no need to start
* the scan state machine in stack. The scan must honour the channel
- * configuration done by the regulatory agent in the wiphy's registered
- * bands. When the scan finishes, ieee80211_scan_completed() must be
- * called; note that it also must be called when the scan cannot finish
- * because the hardware is turned off! Anything else is a bug!
- * Returns a negative error code which will be seen in userspace.
+ * configuration done by the regulatory agent in the wiphy's
+ * registered bands. The hardware (or the driver) needs to make sure
+ * that power save is disabled. When the scan finishes,
+ * ieee80211_scan_completed() must be called; note that it also must
+ * be called when the scan cannot finish because the hardware is
+ * turned off! Anything else is a bug! Returns a negative error code
+ * which will be seen in userspace.
*
* @sw_scan_start: Notifier function that is called just before a software scan
* is started. Can be NULL, if the driver doesn't need this notification.
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index 46f35dc..3bf9839 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -214,6 +214,66 @@ void ieee80211_scan_failed(struct ieee80211_local *local)
local->scan_req = NULL;
}
+/*
+ * inform AP that we will go to sleep so that it will buffer the frames
+ * while we scan
+ */
+static void ieee80211_scan_ps_enable(struct ieee80211_sub_if_data *sdata)
+{
+ struct ieee80211_local *local = sdata->local;
+ bool ps = false;
+
+ /* FIXME: what to do when local->pspolling is true? */
+
+ del_timer_sync(&local->dynamic_ps_timer);
+ cancel_work_sync(&local->dynamic_ps_enable_work);
+
+ if (local->hw.conf.flags & IEEE80211_CONF_PS) {
+ ps = true;
+ local->hw.conf.flags &= ~IEEE80211_CONF_PS;
+ ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
+ }
+
+ if (!ps || !(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK))
+ /*
+ * If power save was enabled, no need to send a nullfunc
+ * frame because AP knows that we are sleeping. But if the
+ * hardware is creating the nullfunc frame for power save
+ * status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not
+ * enabled) and power save was enabled, the firmware just
+ * sent a null frame with power save disabled. So we need
+ * to send a new nullfunc frame to inform the AP that we
+ * are again sleeping.
+ */
+ ieee80211_send_nullfunc(local, sdata, 1);
+}
+
+/* inform AP that we are awake again, unless power save is enabled */
+static void ieee80211_scan_ps_disable(struct ieee80211_sub_if_data *sdata)
+{
+ struct ieee80211_local *local = sdata->local;
+
+ if (!local->powersave)
+ ieee80211_send_nullfunc(local, sdata, 0);
+ else {
+ /*
+ * In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware
+ * will send a nullfunc frame with the powersave bit set
+ * even though the AP already knows that we are sleeping.
+ * This could be avoided by sending a null frame with power
+ * save bit disabled before enabling the power save, but
+ * this doesn't gain anything.
+ *
+ * When IEEE80211_HW_PS_NULLFUNC_STACK is enabled, no need
+ * to send a nullfunc frame because AP already knows that
+ * we are sleeping, let's just enable power save mode in
+ * hardware.
+ */
+ local->hw.conf.flags |= IEEE80211_CONF_PS;
+ ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
+ }
+}
+
void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
{
struct ieee80211_local *local = hw_to_local(hw);
@@ -268,7 +328,7 @@ void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
/* Tell AP we're back */
if (sdata->vif.type == NL80211_IFTYPE_STATION) {
if (sdata->u.mgd.flags & IEEE80211_STA_ASSOCIATED) {
- ieee80211_send_nullfunc(local, sdata, 0);
+ ieee80211_scan_ps_disable(sdata);
netif_tx_wake_all_queues(sdata->dev);
}
} else
@@ -441,7 +501,7 @@ int ieee80211_start_scan(struct ieee80211_sub_if_data *scan_sdata,
if (sdata->vif.type == NL80211_IFTYPE_STATION) {
if (sdata->u.mgd.flags & IEEE80211_STA_ASSOCIATED) {
netif_tx_stop_all_queues(sdata->dev);
- ieee80211_send_nullfunc(local, sdata, 1);
+ ieee80211_scan_ps_enable(sdata);
}
} else
netif_tx_stop_all_queues(sdata->dev);
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