Commit 40b96408 authored by Johannes Berg's avatar Johannes Berg Committed by John W. Linville
Browse files

mac80211: explicitly notify drivers of frame release 



iwlwifi needs to know the number of frames that are
going to be sent to a station while it is asleep so
it can properly handle the uCode blocking of that
station.

Before uAPSD, we got by by telling the device that
a single frame was going to be released whenever we
encountered IEEE80211_TX_CTL_POLL_RESPONSE. With
uAPSD, however, that is no longer possible since
there could be more than a single frame.

To support this model, add a new callback to notify
drivers when frames are going to be released.

Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 5bade101

include/net/mac80211.h

+17 −0
Original line number Diff line number Diff line
@@ -1973,6 +1973,18 @@ enum ieee80211_frame_release_type { 
 *	service period ends, the driver must set %IEEE80211_TX_STATUS_EOSP

 *	on the last frame in the SP.

 *	This callback must be atomic.

 * @allow_buffered_frames: Prepare device to allow the given number of frames

 *	to go out to the given station. The frames will be sent by mac80211

 *	via the usual TX path after this call. The TX information for frames

 *	released will also have the %IEEE80211_TX_CTL_POLL_RESPONSE flag set

 *	and the last one will also have %IEEE80211_TX_STATUS_EOSP set. In case

 *	frames from multiple TIDs are released and the driver might reorder

 *	them between the TIDs, it must set the %IEEE80211_TX_STATUS_EOSP flag

 *	on the last frame and clear it on all others and also handle the EOSP

 *	bit in the QoS header correctly.

 *	The @tids parameter is a bitmap and tells the driver which TIDs the

 *	frames will be on; it will at most have two bits set.

 *	This callback must be atomic.

 */

struct ieee80211_ops {

	void (*tx)(struct ieee80211_hw *hw, struct sk_buff *skb);
@@ -2088,6 +2100,11 @@ struct ieee80211_ops { 
	void (*rssi_callback)(struct ieee80211_hw *hw,

			      enum ieee80211_rssi_event rssi_event);



	void (*allow_buffered_frames)(struct ieee80211_hw *hw,

				      struct ieee80211_sta *sta,

				      u16 tids, int num_frames,

				      enum ieee80211_frame_release_type reason,

				      bool more_data);

	void (*release_buffered_frames)(struct ieee80211_hw *hw,

					struct ieee80211_sta *sta,

					u16 tids, int num_frames,

net/mac80211/driver-ops.h

+15 −0
Original line number Diff line number Diff line
@@ -685,4 +685,19 @@ drv_release_buffered_frames(struct ieee80211_local *local, 
						    more_data);

	trace_drv_return_void(local);

}



static inline void

drv_allow_buffered_frames(struct ieee80211_local *local,

			  struct sta_info *sta, u16 tids, int num_frames,

			  enum ieee80211_frame_release_type reason,

			  bool more_data)

{

	trace_drv_allow_buffered_frames(local, &sta->sta, tids, num_frames,

					reason, more_data);

	if (local->ops->allow_buffered_frames)

		local->ops->allow_buffered_frames(&local->hw, &sta->sta,

						  tids, num_frames, reason,

						  more_data);

	trace_drv_return_void(local);

}

#endif /* __MAC80211_DRIVER_OPS */

net/mac80211/driver-trace.h

+21 −1
Original line number Diff line number Diff line
@@ -1129,7 +1129,7 @@ TRACE_EVENT(drv_rssi_callback, 
	)

);



TRACE_EVENT(drv_release_buffered_frames,

DECLARE_EVENT_CLASS(release_evt,

	TP_PROTO(struct ieee80211_local *local,

		 struct ieee80211_sta *sta,

		 u16 tids, int num_frames,
@@ -1164,6 +1164,26 @@ TRACE_EVENT(drv_release_buffered_frames, 
	)

);



DEFINE_EVENT(release_evt, drv_release_buffered_frames,

	TP_PROTO(struct ieee80211_local *local,

		 struct ieee80211_sta *sta,

		 u16 tids, int num_frames,

		 enum ieee80211_frame_release_type reason,

		 bool more_data),



	TP_ARGS(local, sta, tids, num_frames, reason, more_data)

);



DEFINE_EVENT(release_evt, drv_allow_buffered_frames,

	TP_PROTO(struct ieee80211_local *local,

		 struct ieee80211_sta *sta,

		 u16 tids, int num_frames,

		 enum ieee80211_frame_release_type reason,

		 bool more_data),



	TP_ARGS(local, sta, tids, num_frames, reason, more_data)

);



/*

 * Tracing for API calls that drivers call.

 */

net/mac80211/sta_info.c

+25 −9
Original line number Diff line number Diff line
@@ -1169,7 +1169,7 @@ void ieee80211_sta_ps_deliver_wakeup(struct sta_info *sta) 


static void ieee80211_send_null_response(struct ieee80211_sub_if_data *sdata,

					 struct sta_info *sta, int tid,

					 bool uapsd)

					 enum ieee80211_frame_release_type reason)

{

	struct ieee80211_local *local = sdata->local;

	struct ieee80211_qos_hdr *nullfunc;
@@ -1210,7 +1210,7 @@ static void ieee80211_send_null_response(struct ieee80211_sub_if_data *sdata, 


		nullfunc->qos_ctrl = cpu_to_le16(tid);



		if (uapsd)

		if (reason == IEEE80211_FRAME_RELEASE_UAPSD)

			nullfunc->qos_ctrl |=

				cpu_to_le16(IEEE80211_QOS_CTL_EOSP);

	}
@@ -1227,6 +1227,8 @@ static void ieee80211_send_null_response(struct ieee80211_sub_if_data *sdata, 
		       IEEE80211_TX_STATUS_EOSP |

		       IEEE80211_TX_CTL_REQ_TX_STATUS;



	drv_allow_buffered_frames(local, sta, BIT(tid), 1, reason, false);



	ieee80211_xmit(sdata, skb);

}
@@ -1324,20 +1326,24 @@ ieee80211_sta_ps_deliver_response(struct sta_info *sta, 
		/* This will evaluate to 1, 3, 5 or 7. */

		tid = 7 - ((ffs(~ignored_acs) - 1) << 1);



		ieee80211_send_null_response(sdata, sta, tid,

				reason == IEEE80211_FRAME_RELEASE_UAPSD);

		ieee80211_send_null_response(sdata, sta, tid, reason);

		return;

	}



	if (!driver_release_tids) {

		struct sk_buff_head pending;

		struct sk_buff *skb;

		int num = 0;

		u16 tids = 0;



		skb_queue_head_init(&pending);



		while ((skb = __skb_dequeue(&frames))) {

			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);

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

			u8 *qoshdr = NULL;



			num++;



			/*

			 * Tell TX path to send this frame even though the
@@ -1357,19 +1363,29 @@ ieee80211_sta_ps_deliver_response(struct sta_info *sta, 
				hdr->frame_control |=

					cpu_to_le16(IEEE80211_FCTL_MOREDATA);



			if (reason == IEEE80211_FRAME_RELEASE_UAPSD &&

			    skb_queue_empty(&frames)) {

			if (ieee80211_is_data_qos(hdr->frame_control) ||

			    ieee80211_is_qos_nullfunc(hdr->frame_control))

				qoshdr = ieee80211_get_qos_ctl(hdr);



			/* set EOSP for the frame */

				u8 *p = ieee80211_get_qos_ctl(hdr);

				*p |= IEEE80211_QOS_CTL_EOSP;

			}

			if (reason == IEEE80211_FRAME_RELEASE_UAPSD &&

			    qoshdr && skb_queue_empty(&frames))

				*qoshdr |= IEEE80211_QOS_CTL_EOSP;



			info->flags |= IEEE80211_TX_STATUS_EOSP |

				       IEEE80211_TX_CTL_REQ_TX_STATUS;



			if (qoshdr)

				tids |= BIT(*qoshdr & IEEE80211_QOS_CTL_TID_MASK);

			else

				tids |= BIT(0);



			__skb_queue_tail(&pending, skb);

		}



		drv_allow_buffered_frames(local, sta, tids, num,

					  reason, more_data);



		ieee80211_add_pending_skbs(local, &pending);



		sta_info_recalc_tim(sta);

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