Commit 43552be1 authored by Thomas Pedersen's avatar Thomas Pedersen Committed by Johannes Berg
Browse files

mac80211: update adjusting TBTT bit in beacon 



This regression was introduced in "mac80211: cache mesh
beacon".

mesh_sync_offset_adjust_tbtt()  was assuming that the
beacon would be rebuilt in every single pre-tbtt
interrupt, but now the beacon update happens on the
workqueue, and it must be ready for immediate delivery to
the driver.

Save a pointer to the meshconf IE in the beacon_data (this
works because both the IE pointer and beacon buffer are
protected by the same rcu_{dereference,assign_pointer}())
for quick updates during pre-tbtt. This is faster and a
little prettier than iterating over the elements to find
the meshconf IE every time.

Signed-off-by: default avatarThomas Pedersen <thomas@cozybit.com>
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent d43c6b6e

net/mac80211/ieee80211_i.h

+8 −1
Original line number Diff line number Diff line
@@ -232,6 +232,7 @@ struct ieee80211_rx_data { 
struct beacon_data {

	u8 *head, *tail;

	int head_len, tail_len;

	struct ieee80211_meshconf_ie *meshconf;

	struct rcu_head rcu_head;

};
@@ -540,7 +541,10 @@ struct ieee80211_mesh_sync_ops { 
			     struct ieee80211_mgmt *mgmt,

			     struct ieee802_11_elems *elems,

			     struct ieee80211_rx_status *rx_status);

	void (*adjust_tbtt)(struct ieee80211_sub_if_data *sdata);



	/* should be called with beacon_data under RCU read lock */

	void (*adjust_tbtt)(struct ieee80211_sub_if_data *sdata,

			    struct beacon_data *beacon);

	/* add other framework functions here */

};
@@ -614,6 +618,9 @@ struct ieee80211_if_mesh { 
	bool chsw_init;

	u8 chsw_ttl;

	u16 pre_value;



	/* offset from skb->data while building IE */

	int meshconf_offset;

};



#ifdef CONFIG_MAC80211_MESH

net/mac80211/mesh.c

+5 −0
Original line number Diff line number Diff line
@@ -259,6 +259,9 @@ int mesh_add_meshconf_ie(struct ieee80211_sub_if_data *sdata, 
	*pos++ = WLAN_EID_MESH_CONFIG;

	*pos++ = meshconf_len;



	/* save a pointer for quick updates in pre-tbtt */

	ifmsh->meshconf_offset = pos - skb->data;



	/* Active path selection protocol ID */

	*pos++ = ifmsh->mesh_pp_id;

	/* Active path selection metric ID   */
@@ -723,6 +726,8 @@ ieee80211_mesh_build_beacon(struct ieee80211_if_mesh *ifmsh) 


	bcn->tail_len = skb->len;

	memcpy(bcn->tail, skb->data, bcn->tail_len);

	bcn->meshconf = (struct ieee80211_meshconf_ie *)

					(bcn->tail + ifmsh->meshconf_offset);



	dev_kfree_skb(skb);

	rcu_assign_pointer(ifmsh->beacon, bcn);

net/mac80211/mesh_sync.c

+8 −1
Original line number Diff line number Diff line
@@ -164,12 +164,15 @@ no_sync: 
	rcu_read_unlock();

}



static void mesh_sync_offset_adjust_tbtt(struct ieee80211_sub_if_data *sdata)

static void mesh_sync_offset_adjust_tbtt(struct ieee80211_sub_if_data *sdata,

					 struct beacon_data *beacon)

{

	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;

	u8 cap;



	WARN_ON(ifmsh->mesh_sp_id != IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET);

	BUG_ON(!rcu_read_lock_held());

	cap = beacon->meshconf->meshconf_cap;



	spin_lock_bh(&ifmsh->sync_offset_lock);
@@ -194,6 +197,10 @@ static void mesh_sync_offset_adjust_tbtt(struct ieee80211_sub_if_data *sdata) 
		ifmsh->adjusting_tbtt = false;

	}

	spin_unlock_bh(&ifmsh->sync_offset_lock);



	beacon->meshconf->meshconf_cap = ifmsh->adjusting_tbtt ?

			IEEE80211_MESHCONF_CAPAB_TBTT_ADJUSTING | cap :

			~IEEE80211_MESHCONF_CAPAB_TBTT_ADJUSTING & cap;

}



static const struct sync_method sync_methods[] = {

net/mac80211/tx.c

+1 −2
Original line number Diff line number Diff line
@@ -2604,8 +2604,7 @@ struct sk_buff *ieee80211_beacon_get_tim(struct ieee80211_hw *hw, 
			ieee80211_update_csa(sdata, bcn);



		if (ifmsh->sync_ops)

			ifmsh->sync_ops->adjust_tbtt(

						sdata);

			ifmsh->sync_ops->adjust_tbtt(sdata, bcn);



		skb = dev_alloc_skb(local->tx_headroom +

				    bcn->head_len +

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