From: Thomas Pedersen <thomas@xxxxxxxxxxx>
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: Thomas Pedersen <thomas@xxxxxxxxxxx>
---
net/mac80211/ieee80211_i.h | 9 ++++++++-
net/mac80211/mesh.c | 5 +++++
net/mac80211/mesh_sync.c | 9 ++++++++-
net/mac80211/tx.c | 3 +--
4 files changed, 22 insertions(+), 4 deletions(-)
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 32bae21..ec1d4a6 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -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
diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c
index 1174157..86c2d41 100644
--- a/net/mac80211/mesh.c
+++ b/net/mac80211/mesh.c
@@ -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);
diff --git a/net/mac80211/mesh_sync.c b/net/mac80211/mesh_sync.c
index d1cf2d5..2bc5dc2 100644
--- a/net/mac80211/mesh_sync.c
+++ b/net/mac80211/mesh_sync.c
@@ -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[] = {
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 6d59e21..d758509 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -2602,8 +2602,7 @@ 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 +
--
1.7.10.4
--
To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
