diff options
Diffstat (limited to 'net/mac80211/scan.c')
| -rw-r--r-- | net/mac80211/scan.c | 77 |
1 files changed, 75 insertions, 2 deletions
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c index 5030a3c8750..3bf9839f591 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 @@ -409,6 +469,19 @@ int ieee80211_start_scan(struct ieee80211_sub_if_data *scan_sdata, return 0; } + /* + * Hardware/driver doesn't support hw_scan, so use software + * scanning instead. First send a nullfunc frame with power save + * bit on so that AP will buffer the frames for us while we are not + * listening, then send probe requests to each channel and wait for + * the responses. After all channels are scanned, tune back to the + * original channel and send a nullfunc frame with power save bit + * off to trigger the AP to send us all the buffered frames. + * + * Note that while local->sw_scanning is true everything else but + * nullfunc frames and probe requests will be dropped in + * ieee80211_tx_h_check_assoc(). + */ local->sw_scanning = true; if (local->ops->sw_scan_start) local->ops->sw_scan_start(local_to_hw(local)); @@ -428,7 +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); |