Commit 46fa38e8 authored by Johannes Berg's avatar Johannes Berg
Browse files

mac80211: allow software PS-Poll/U-APSD with AP_LINK_PS 



When using RSS, frames might not be processed in the correct order,
and thus AP_LINK_PS must be used; most likely with firmware keeping
track of the powersave state, this is the case in iwlwifi now.

In this case, the driver can use ieee80211_sta_ps_transition() to
still have mac80211 manage powersave buffering. However, for U-APSD
and PS-Poll this isn't sufficient. If the device can't manage that
entirely on its own, mac80211's code should be used.

To allow this, export two functions: ieee80211_sta_uapsd_trigger()
and ieee80211_sta_pspoll().

Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent 53873f13

include/net/mac80211.h

+27 −0
Original line number Diff line number Diff line
@@ -3996,6 +3996,33 @@ static inline int ieee80211_sta_ps_transition_ni(struct ieee80211_sta *sta, 
	return ret;

}



/**

 * ieee80211_sta_pspoll - PS-Poll frame received

 * @sta: currently connected station

 *

 * When operating in AP mode with the %IEEE80211_HW_AP_LINK_PS flag set,

 * use this function to inform mac80211 that a PS-Poll frame from a

 * connected station was received.

 * This must be used in conjunction with ieee80211_sta_ps_transition()

 * and possibly ieee80211_sta_uapsd_trigger(); calls to all three must

 * be serialized.

 */

void ieee80211_sta_pspoll(struct ieee80211_sta *sta);



/**

 * ieee80211_sta_uapsd_trigger - (potential) U-APSD trigger frame received

 * @sta: currently connected station

 * @tid: TID of the received (potential) trigger frame

 *

 * When operating in AP mode with the %IEEE80211_HW_AP_LINK_PS flag set,

 * use this function to inform mac80211 that a (potential) trigger frame

 * from a connected station was received.

 * This must be used in conjunction with ieee80211_sta_ps_transition()

 * and possibly ieee80211_sta_pspoll(); calls to all three must be

 * serialized.

 */

void ieee80211_sta_uapsd_trigger(struct ieee80211_sta *sta, u8 tid);



/*

 * The TX headroom reserved by mac80211 for its own tx_status functions.

 * This is enough for the radiotap header.

net/mac80211/rx.c

+44 −26
Original line number Diff line number Diff line
@@ -1319,13 +1319,52 @@ int ieee80211_sta_ps_transition(struct ieee80211_sta *pubsta, bool start) 
}

EXPORT_SYMBOL(ieee80211_sta_ps_transition);



void ieee80211_sta_pspoll(struct ieee80211_sta *pubsta)

{

	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);



	if (test_sta_flag(sta, WLAN_STA_SP))

		return;



	if (!test_sta_flag(sta, WLAN_STA_PS_DRIVER))

		ieee80211_sta_ps_deliver_poll_response(sta);

	else

		set_sta_flag(sta, WLAN_STA_PSPOLL);

}

EXPORT_SYMBOL(ieee80211_sta_pspoll);



void ieee80211_sta_uapsd_trigger(struct ieee80211_sta *pubsta, u8 tid)

{

	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);

	u8 ac = ieee802_1d_to_ac[tid & 7];



	/*

	 * If this AC is not trigger-enabled do nothing.

	 *

	 * NB: This could/should check a separate bitmap of trigger-

	 * enabled queues, but for now we only implement uAPSD w/o

	 * TSPEC changes to the ACs, so they're always the same.

	 */

	if (!(sta->sta.uapsd_queues & BIT(ac)))

		return;



	/* if we are in a service period, do nothing */

	if (test_sta_flag(sta, WLAN_STA_SP))

		return;



	if (!test_sta_flag(sta, WLAN_STA_PS_DRIVER))

		ieee80211_sta_ps_deliver_uapsd(sta);

	else

		set_sta_flag(sta, WLAN_STA_UAPSD);

}

EXPORT_SYMBOL(ieee80211_sta_uapsd_trigger);



static ieee80211_rx_result debug_noinline

ieee80211_rx_h_uapsd_and_pspoll(struct ieee80211_rx_data *rx)

{

	struct ieee80211_sub_if_data *sdata = rx->sdata;

	struct ieee80211_hdr *hdr = (void *)rx->skb->data;

	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);

	int tid, ac;



	if (!rx->sta)

		return RX_CONTINUE;
@@ -1351,12 +1390,7 @@ ieee80211_rx_h_uapsd_and_pspoll(struct ieee80211_rx_data *rx) 
		return RX_CONTINUE;



	if (unlikely(ieee80211_is_pspoll(hdr->frame_control))) {

		if (!test_sta_flag(rx->sta, WLAN_STA_SP)) {

			if (!test_sta_flag(rx->sta, WLAN_STA_PS_DRIVER))

				ieee80211_sta_ps_deliver_poll_response(rx->sta);

			else

				set_sta_flag(rx->sta, WLAN_STA_PSPOLL);

		}

		ieee80211_sta_pspoll(&rx->sta->sta);



		/* Free PS Poll skb here instead of returning RX_DROP that would

		 * count as an dropped frame. */
@@ -1368,27 +1402,11 @@ ieee80211_rx_h_uapsd_and_pspoll(struct ieee80211_rx_data *rx) 
		   ieee80211_has_pm(hdr->frame_control) &&

		   (ieee80211_is_data_qos(hdr->frame_control) ||

		    ieee80211_is_qos_nullfunc(hdr->frame_control))) {

		tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;

		ac = ieee802_1d_to_ac[tid & 7];

		u8 tid;



		/*

		 * If this AC is not trigger-enabled do nothing.

		 *

		 * NB: This could/should check a separate bitmap of trigger-

		 * enabled queues, but for now we only implement uAPSD w/o

		 * TSPEC changes to the ACs, so they're always the same.

		 */

		if (!(rx->sta->sta.uapsd_queues & BIT(ac)))

			return RX_CONTINUE;



		/* if we are in a service period, do nothing */

		if (test_sta_flag(rx->sta, WLAN_STA_SP))

			return RX_CONTINUE;

		tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;



		if (!test_sta_flag(rx->sta, WLAN_STA_PS_DRIVER))

			ieee80211_sta_ps_deliver_uapsd(rx->sta);

		else

			set_sta_flag(rx->sta, WLAN_STA_UAPSD);

		ieee80211_sta_uapsd_trigger(&rx->sta->sta, tid);

	}



	return RX_CONTINUE;

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