mwifiex: delete AP TX queues when bridged packets reach threshold

Delete packets from TX queues for this mwifiex_private structure
when bridged packet count reaches maximum threshold. Bridged packets
from each RA List are deleted till they fall to low threshold of 128.

Signed-off-by: Avinash Patil <patila@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

4 files changed, 69 insertions, 2 deletions

diff --git a/drivers/net/wireless/mwifiex/decl.h b/drivers/net/wireless/mwifiex/decl.h
index 94cc09d48444..a5993475daef 100644
--- a/drivers/net/wireless/mwifiex/decl.h
+++ b/drivers/net/wireless/mwifiex/decl.h
@@ -75,7 +75,8 @@
 #define MWIFIEX_BUF_FLAG_REQUEUED_PKT      BIT(0)
 #define MWIFIEX_BUF_FLAG_BRIDGED_PKT       BIT(1)
 
-#define MWIFIEX_BRIDGED_PKTS_THRESHOLD     1024
+#define MWIFIEX_BRIDGED_PKTS_THR_HIGH      1024
+#define MWIFIEX_BRIDGED_PKTS_THR_LOW        128
 
 enum mwifiex_bss_type {
         MWIFIEX_BSS_TYPE_STA = 0,
diff --git a/drivers/net/wireless/mwifiex/init.c b/drivers/net/wireless/mwifiex/init.c
index caaf4bd56b30..fb86cec1b5cd 100644
--- a/drivers/net/wireless/mwifiex/init.c
+++ b/drivers/net/wireless/mwifiex/init.c
@@ -135,6 +135,7 @@ int mwifiex_init_priv(struct mwifiex_private *priv)
 
         priv->csa_chan = 0;
         priv->csa_expire_time = 0;
+        priv->del_list_idx = 0;
 
         return mwifiex_add_bss_prio_tbl(priv);
 }
diff --git a/drivers/net/wireless/mwifiex/main.h b/drivers/net/wireless/mwifiex/main.h
index 761e5927eee3..5db05435d412 100644
--- a/drivers/net/wireless/mwifiex/main.h
+++ b/drivers/net/wireless/mwifiex/main.h
@@ -515,6 +515,7 @@ struct mwifiex_private {
         bool scan_aborting;
         u8 csa_chan;
         unsigned long csa_expire_time;
+        u8 del_list_idx;
 };
 
 enum mwifiex_ba_status {
diff --git a/drivers/net/wireless/mwifiex/uap_txrx.c b/drivers/net/wireless/mwifiex/uap_txrx.c
index 11df2b2f8923..1cfe5a738c47 100644
--- a/drivers/net/wireless/mwifiex/uap_txrx.c
+++ b/drivers/net/wireless/mwifiex/uap_txrx.c
@@ -24,6 +24,69 @@
 #include "11n_aggr.h"
 #include "11n_rxreorder.h"
 
+/* This function checks if particular RA list has packets more than low bridge
+ * packet threshold and then deletes packet from this RA list.
+ * Function deletes packets from such RA list and returns true. If no such list
+ * is found, false is returned.
+ */
+static bool
+mwifiex_uap_del_tx_pkts_in_ralist(struct mwifiex_private *priv,
+                                  struct list_head *ra_list_head)
+{
+        struct mwifiex_ra_list_tbl *ra_list;
+        struct sk_buff *skb, *tmp;
+        bool pkt_deleted = false;
+        struct mwifiex_txinfo *tx_info;
+        struct mwifiex_adapter *adapter = priv->adapter;
+
+        list_for_each_entry(ra_list, ra_list_head, list) {
+                if (skb_queue_empty(&ra_list->skb_head))
+                        continue;
+
+                skb_queue_walk_safe(&ra_list->skb_head, skb, tmp) {
+                        tx_info = MWIFIEX_SKB_TXCB(skb);
+                        if (tx_info->flags & MWIFIEX_BUF_FLAG_BRIDGED_PKT) {
+                                __skb_unlink(skb, &ra_list->skb_head);
+                                mwifiex_write_data_complete(adapter, skb, 0,
+                                                            -1);
+                                atomic_dec(&priv->wmm.tx_pkts_queued);
+                                pkt_deleted = true;
+                        }
+                        if ((atomic_read(&adapter->pending_bridged_pkts) <=
+                                             MWIFIEX_BRIDGED_PKTS_THR_LOW))
+                                break;
+                }
+        }
+
+        return pkt_deleted;
+}
+
+/* This function deletes packets from particular RA List. RA list index
+ * from which packets are deleted is preserved so that packets from next RA
+ * list are deleted upon subsequent call thus maintaining fairness.
+ */
+static void mwifiex_uap_cleanup_tx_queues(struct mwifiex_private *priv)
+{
+        unsigned long flags;
+        struct list_head *ra_list;
+        int i;
+
+        spin_lock_irqsave(&priv->wmm.ra_list_spinlock, flags);
+
+        for (i = 0; i < MAX_NUM_TID; i++, priv->del_list_idx++) {
+                if (priv->del_list_idx == MAX_NUM_TID)
+                        priv->del_list_idx = 0;
+                ra_list = &priv->wmm.tid_tbl_ptr[priv->del_list_idx].ra_list;
+                if (mwifiex_uap_del_tx_pkts_in_ralist(priv, ra_list)) {
+                        priv->del_list_idx++;
+                        break;
+                }
+        }
+
+        spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock, flags);
+}
+
+
 static void mwifiex_uap_queue_bridged_pkt(struct mwifiex_private *priv,
                                          struct sk_buff *skb)
 {
@@ -40,10 +103,11 @@ static void mwifiex_uap_queue_bridged_pkt(struct mwifiex_private *priv,
         rx_pkt_hdr = (void *)uap_rx_pd + le16_to_cpu(uap_rx_pd->rx_pkt_offset);
 
         if ((atomic_read(&adapter->pending_bridged_pkts) >=
-                                             MWIFIEX_BRIDGED_PKTS_THRESHOLD)) {
+                                             MWIFIEX_BRIDGED_PKTS_THR_HIGH)) {
                 dev_err(priv->adapter->dev,
                         "Tx: Bridge packet limit reached. Drop packet!\n");
                 kfree_skb(skb);
+                mwifiex_uap_cleanup_tx_queues(priv);
                 return;
         }