mwifiex: reduce CPU usage by tracking tx_pkts_queued

This patch adds tx_pkts_queued to track number of packets being
enqueued & dequeued so that mwifiex_wmm_lists_empty() evaluation
is lightweight.

Signed-off-by: Marc Yang <yangyang@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 19 insertions, 10 deletions

diff --git a/drivers/net/wireless/mwifiex/11n_aggr.c b/drivers/net/wireless/mwifiex/11n_aggr.c
index d3d5e0853c45..f807447e4d99 100644
--- a/drivers/net/wireless/mwifiex/11n_aggr.c
+++ b/drivers/net/wireless/mwifiex/11n_aggr.c
@@ -196,6 +196,8 @@ mwifiex_11n_aggregate_pkt(struct mwifiex_private *priv,
                 if (skb_src)
                         pra_list->total_pkts_size -= skb_src->len;
 
+                atomic_dec(&priv->wmm.tx_pkts_queued);
+
                 spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock,
                                        ra_list_flags);
                 mwifiex_11n_form_amsdu_pkt(skb_aggr, skb_src, &pad);
@@ -257,6 +259,8 @@ mwifiex_11n_aggregate_pkt(struct mwifiex_private *priv,
 
                 pra_list->total_pkts_size += skb_aggr->len;
 
+                atomic_inc(&priv->wmm.tx_pkts_queued);
+
                 tx_info_aggr->flags |= MWIFIEX_BUF_FLAG_REQUEUED_PKT;
                 spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock,
                                        ra_list_flags);
diff --git a/drivers/net/wireless/mwifiex/main.h b/drivers/net/wireless/mwifiex/main.h
index 672701dc2721..537b40dc016e 100644
--- a/drivers/net/wireless/mwifiex/main.h
+++ b/drivers/net/wireless/mwifiex/main.h
@@ -213,7 +213,8 @@ struct mwifiex_wmm_desc {
         u32 drv_pkt_delay_max;
         u8 queue_priority[IEEE80211_MAX_QUEUES];
         u32 user_pri_pkt_tx_ctrl[WMM_HIGHEST_PRIORITY + 1];     /* UP: 0 to 7 */
-
+        /* Number of transmit packets queued */
+        atomic_t tx_pkts_queued;
 };
 
 struct mwifiex_802_11_security {
diff --git a/drivers/net/wireless/mwifiex/wmm.c b/drivers/net/wireless/mwifiex/wmm.c
index faa09e32902e..52d218512c1e 100644
--- a/drivers/net/wireless/mwifiex/wmm.c
+++ b/drivers/net/wireless/mwifiex/wmm.c
@@ -399,6 +399,8 @@ mwifiex_wmm_init(struct mwifiex_adapter *adapter)
                 priv->add_ba_param.timeout = MWIFIEX_DEFAULT_BLOCK_ACK_TIMEOUT;
                 priv->add_ba_param.tx_win_size = MWIFIEX_AMPDU_DEF_TXWINSIZE;
                 priv->add_ba_param.rx_win_size = MWIFIEX_AMPDU_DEF_RXWINSIZE;
+
+                atomic_set(&priv->wmm.tx_pkts_queued, 0);
         }
 }
 
@@ -408,17 +410,13 @@ mwifiex_wmm_init(struct mwifiex_adapter *adapter)
 int
 mwifiex_wmm_lists_empty(struct mwifiex_adapter *adapter)
 {
-        int i, j;
+        int i;
         struct mwifiex_private *priv;
 
-        for (j = 0; j < adapter->priv_num; ++j) {
-                priv = adapter->priv[j];
-                if (priv) {
-                        for (i = 0; i < MAX_NUM_TID; i++)
-                                if (!mwifiex_wmm_is_ra_list_empty(
-                                             &priv->wmm.tid_tbl_ptr[i].ra_list))
-                                        return false;
-                }
+        for (i = 0; i < adapter->priv_num; ++i) {
+                priv = adapter->priv[i];
+                if (priv && atomic_read(&priv->wmm.tx_pkts_queued))
+                                return false;
         }
 
         return true;
@@ -468,6 +466,8 @@ static void mwifiex_wmm_cleanup_queues(struct mwifiex_private *priv)
         for (i = 0; i < MAX_NUM_TID; i++)
                 mwifiex_wmm_del_pkts_in_ralist(priv, &priv->wmm.tid_tbl_ptr[i].
                                                      ra_list);
+
+        atomic_set(&priv->wmm.tx_pkts_queued, 0);
 }
 
 /*
@@ -638,6 +638,8 @@ mwifiex_wmm_add_buf_txqueue(struct mwifiex_adapter *adapter,
 
         ra_list->total_pkts_size += skb->len;
 
+        atomic_inc(&priv->wmm.tx_pkts_queued);
+
         spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock, flags);
 }
 
@@ -1028,6 +1030,7 @@ mwifiex_send_single_packet(struct mwifiex_private *priv,
                                 .bss_prio_cur->list,
                                 struct mwifiex_bss_prio_node,
                                 list);
+                atomic_dec(&priv->wmm.tx_pkts_queued);
                 spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock,
                                        ra_list_flags);
         }
@@ -1134,6 +1137,7 @@ mwifiex_send_processed_packet(struct mwifiex_private *priv,
                                 .bss_prio_cur->list,
                                 struct mwifiex_bss_prio_node,
                                 list);
+                atomic_dec(&priv->wmm.tx_pkts_queued);
                 spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock,
                                        ra_list_flags);
         }