4 files changed, 89 insertions, 39 deletions

diff --git a/drivers/net/wireless/wl12xx/main.c b/drivers/net/wireless/wl12xx/main.c
index 1cd396306e7b..7dce24c0b331 100644
--- a/drivers/net/wireless/wl12xx/main.c
+++ b/drivers/net/wireless/wl12xx/main.c
@@ -1212,20 +1212,46 @@ static void wl1271_op_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
         spin_unlock_irqrestore(&wl->wl_lock, flags);
 }
 
-#define TX_DUMMY_PACKET_SIZE 1400
 int wl1271_tx_dummy_packet(struct wl1271 *wl)
 {
-        struct sk_buff *skb = NULL;
+        unsigned long flags;
+
+        spin_lock_irqsave(&wl->wl_lock, flags);
+        set_bit(WL1271_FLAG_DUMMY_PACKET_PENDING, &wl->flags);
+        wl->tx_queue_count++;
+        spin_unlock_irqrestore(&wl->wl_lock, flags);
+
+        /* The FW is low on RX memory blocks, so send the dummy packet asap */
+        if (!test_bit(WL1271_FLAG_FW_TX_BUSY, &wl->flags))
+                wl1271_tx_work_locked(wl);
+
+        /*
+         * If the FW TX is busy, TX work will be scheduled by the threaded
+         * interrupt handler function
+         */
+        return 0;
+}
+
+/*
+ * The size of the dummy packet should be at least 1400 bytes. However, in
+ * order to minimize the number of bus transactions, aligning it to 512 bytes
+ * boundaries could be beneficial, performance wise
+ */
+#define TOTAL_TX_DUMMY_PACKET_SIZE (ALIGN(1400, 512))
+
+struct sk_buff *wl12xx_alloc_dummy_packet(struct wl1271 *wl)
+{
+        struct sk_buff *skb;
         struct ieee80211_hdr_3addr *hdr;
-        int ret = 0;
+        unsigned int dummy_packet_size;
+
+        dummy_packet_size = TOTAL_TX_DUMMY_PACKET_SIZE -
+                            sizeof(struct wl1271_tx_hw_descr) - sizeof(*hdr);
 
-        skb = dev_alloc_skb(
-                sizeof(struct wl1271_tx_hw_descr) + sizeof(*hdr) +
-                TX_DUMMY_PACKET_SIZE);
+        skb = dev_alloc_skb(TOTAL_TX_DUMMY_PACKET_SIZE);
         if (!skb) {
-                wl1271_warning("failed to allocate buffer for dummy packet");
-                ret = -ENOMEM;
-                goto out;
+                wl1271_warning("Failed to allocate a dummy packet skb");
+                return NULL;
         }
 
         skb_reserve(skb, sizeof(struct wl1271_tx_hw_descr));
@@ -1233,29 +1259,22 @@ int wl1271_tx_dummy_packet(struct wl1271 *wl)
         hdr = (struct ieee80211_hdr_3addr *) skb_put(skb, sizeof(*hdr));
         memset(hdr, 0, sizeof(*hdr));
         hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_DATA |
-                                         IEEE80211_FCTL_TODS  |
-                                         IEEE80211_STYPE_NULLFUNC);
-
-        memcpy(hdr->addr1, wl->bssid, ETH_ALEN);
-        memcpy(hdr->addr2, wl->mac_addr, ETH_ALEN);
-        memcpy(hdr->addr3, wl->bssid, ETH_ALEN);
+                                         IEEE80211_STYPE_NULLFUNC |
+                                         IEEE80211_FCTL_TODS);
 
-        skb_put(skb, TX_DUMMY_PACKET_SIZE);
+        memset(skb_put(skb, dummy_packet_size), 0, dummy_packet_size);
 
-        memset(skb->data, 0, TX_DUMMY_PACKET_SIZE);
-
-        skb->pkt_type = TX_PKT_TYPE_DUMMY_REQ;
         /* Dummy packets require the TID to be management */
         skb->priority = WL1271_TID_MGMT;
-        /* CONF_TX_AC_VO */
-        skb->queue_mapping = 0;
 
-        wl1271_op_tx(wl->hw, skb);
+        /* Initialize all fields that might be used */
+        skb->queue_mapping = 0;
+        memset(IEEE80211_SKB_CB(skb), 0, sizeof(struct ieee80211_tx_info));
 
-out:
-        return ret;
+        return skb;
 }
 
+
 static struct notifier_block wl1271_dev_notifier = {
         .notifier_call = wl1271_dev_notify,
 };
@@ -3653,11 +3672,17 @@ struct ieee80211_hw *wl1271_alloc_hw(void)
                 goto err_hw;
         }
 
+        wl->dummy_packet = wl12xx_alloc_dummy_packet(wl);
+        if (!wl->dummy_packet) {
+                ret = -ENOMEM;
+                goto err_aggr;
+        }
+
         /* Register platform device */
         ret = platform_device_register(wl->plat_dev);
         if (ret) {
                 wl1271_error("couldn't register platform device");
-                goto err_aggr;
+                goto err_dummy_packet;
         }
         dev_set_drvdata(&wl->plat_dev->dev, wl);
 
@@ -3683,6 +3708,9 @@ err_bt_coex_state:
 err_platform:
         platform_device_unregister(wl->plat_dev);
 
+err_dummy_packet:
+        dev_kfree_skb(wl->dummy_packet);
+
 err_aggr:
         free_pages((unsigned long)wl->aggr_buf, order);
 
@@ -3702,6 +3730,7 @@ EXPORT_SYMBOL_GPL(wl1271_alloc_hw);
 int wl1271_free_hw(struct wl1271 *wl)
 {
         platform_device_unregister(wl->plat_dev);
+        dev_kfree_skb(wl->dummy_packet);
         free_pages((unsigned long)wl->aggr_buf,
                         get_order(WL1271_AGGR_BUFFER_SIZE));
         kfree(wl->plat_dev);
diff --git a/drivers/net/wireless/wl12xx/tx.c b/drivers/net/wireless/wl12xx/tx.c
index ba69ba7051fa..67245ad396ea 100644
--- a/drivers/net/wireless/wl12xx/tx.c
+++ b/drivers/net/wireless/wl12xx/tx.c
@@ -219,6 +219,11 @@ static int wl1271_tx_allocate(struct wl1271 *wl, struct sk_buff *skb, u32 extra,
         return ret;
 }
 
+static bool wl12xx_is_dummy_packet(struct wl1271 *wl, struct sk_buff *skb)
+{
+        return wl->dummy_packet == skb;
+}
+
 static void wl1271_tx_fill_hdr(struct wl1271 *wl, struct sk_buff *skb,
                               u32 extra, struct ieee80211_tx_info *control,
                               u8 hlid)
@@ -253,7 +258,7 @@ static void wl1271_tx_fill_hdr(struct wl1271 *wl, struct sk_buff *skb,
         ac = wl1271_tx_get_queue(skb_get_queue_mapping(skb));
         desc->tid = skb->priority;
 
-        if (skb->pkt_type == TX_PKT_TYPE_DUMMY_REQ) {
+        if (wl12xx_is_dummy_packet(wl, skb)) {
                 /*
                  * FW expects the dummy packet to have an invalid session id -
                  * any session id that is different than the one set in the join
@@ -396,6 +401,10 @@ static int wl1271_prepare_tx_frame(struct wl1271 *wl, struct sk_buff *skb,
         memcpy(wl->aggr_buf + buf_offset, skb->data, skb->len);
         memset(wl->aggr_buf + buf_offset + skb->len, 0, total_len - skb->len);
 
+        /* Revert side effects in the dummy packet skb, so it can be reused */
+        if (wl12xx_is_dummy_packet(wl, skb))
+                skb_pull(skb, sizeof(struct wl1271_tx_hw_descr));
+
         return total_len;
 }
 
@@ -508,10 +517,23 @@ out:
 
 static struct sk_buff *wl1271_skb_dequeue(struct wl1271 *wl)
 {
+        unsigned long flags;
+        struct sk_buff *skb = NULL;
+
         if (wl->bss_type == BSS_TYPE_AP_BSS)
-                return wl1271_ap_skb_dequeue(wl);
+                skb = wl1271_ap_skb_dequeue(wl);
+        else
+                skb = wl1271_sta_skb_dequeue(wl);
 
-        return wl1271_sta_skb_dequeue(wl);
+        if (!skb &&
+            test_and_clear_bit(WL1271_FLAG_DUMMY_PACKET_PENDING, &wl->flags)) {
+                skb = wl->dummy_packet;
+                spin_lock_irqsave(&wl->wl_lock, flags);
+                wl->tx_queue_count--;
+                spin_unlock_irqrestore(&wl->wl_lock, flags);
+        }
+
+        return skb;
 }
 
 static void wl1271_skb_queue_head(struct wl1271 *wl, struct sk_buff *skb)
@@ -519,7 +541,9 @@ static void wl1271_skb_queue_head(struct wl1271 *wl, struct sk_buff *skb)
         unsigned long flags;
         int q = wl1271_tx_get_queue(skb_get_queue_mapping(skb));
 
-        if (wl->bss_type == BSS_TYPE_AP_BSS) {
+        if (wl12xx_is_dummy_packet(wl, skb)) {
+                set_bit(WL1271_FLAG_DUMMY_PACKET_PENDING, &wl->flags);
+        } else if (wl->bss_type == BSS_TYPE_AP_BSS) {
                 u8 hlid = wl1271_tx_get_hlid(skb);
                 skb_queue_head(&wl->links[hlid].tx_queue[q], skb);
 
@@ -628,8 +652,7 @@ static void wl1271_tx_complete_packet(struct wl1271 *wl,
         skb = wl->tx_frames[id];
         info = IEEE80211_SKB_CB(skb);
 
-        if (skb->pkt_type == TX_PKT_TYPE_DUMMY_REQ) {
-                dev_kfree_skb(skb);
+        if (wl12xx_is_dummy_packet(wl, skb)) {
                 wl1271_free_tx_id(wl, id);
                 return;
         }
@@ -764,9 +787,7 @@ void wl1271_tx_reset(struct wl1271 *wl)
                                 wl1271_debug(DEBUG_TX, "freeing skb 0x%p",
                                              skb);
 
-                                if (skb->pkt_type == TX_PKT_TYPE_DUMMY_REQ) {
-                                        dev_kfree_skb(skb);
-                                } else {
+                                if (!wl12xx_is_dummy_packet(wl, skb)) {
                                         info = IEEE80211_SKB_CB(skb);
                                         info->status.rates[0].idx = -1;
                                         info->status.rates[0].count = 0;
@@ -792,9 +813,7 @@ void wl1271_tx_reset(struct wl1271 *wl)
                 wl1271_free_tx_id(wl, i);
                 wl1271_debug(DEBUG_TX, "freeing skb 0x%p", skb);
 
-                if (skb->pkt_type == TX_PKT_TYPE_DUMMY_REQ) {
-                        dev_kfree_skb(skb);
-                } else {
+                if (!wl12xx_is_dummy_packet(wl, skb)) {
                         /*
                          * Remove private headers before passing the skb to
                          * mac80211
diff --git a/drivers/net/wireless/wl12xx/tx.h b/drivers/net/wireless/wl12xx/tx.h
index d6b05d980626..fc7835c4cf63 100644
--- a/drivers/net/wireless/wl12xx/tx.h
+++ b/drivers/net/wireless/wl12xx/tx.h
@@ -42,8 +42,6 @@
 #define TX_HW_ATTR_TX_CMPLT_REQ          BIT(12)
 #define TX_HW_ATTR_TX_DUMMY_REQ          BIT(13)
 
-#define TX_PKT_TYPE_DUMMY_REQ            5
-
 #define TX_HW_ATTR_OFST_SAVE_RETRIES     0
 #define TX_HW_ATTR_OFST_HEADER_PAD       1
 #define TX_HW_ATTR_OFST_SESSION_COUNTER  2
diff --git a/drivers/net/wireless/wl12xx/wl12xx.h b/drivers/net/wireless/wl12xx/wl12xx.h
index c7c42b687f5e..1b430d2aec4e 100644
--- a/drivers/net/wireless/wl12xx/wl12xx.h
+++ b/drivers/net/wireless/wl12xx/wl12xx.h
@@ -356,6 +356,7 @@ enum wl12xx_flags {
         WL1271_FLAG_FW_TX_BUSY,
         WL1271_FLAG_AP_STARTED,
         WL1271_FLAG_IF_INITIALIZED,
+        WL1271_FLAG_DUMMY_PACKET_PENDING,
 };
 
 struct wl1271_link {
@@ -461,6 +462,9 @@ struct wl1271 {
         /* Intermediate buffer, used for packet aggregation */
         u8 *aggr_buf;
 
+        /* Reusable dummy packet template */
+        struct sk_buff *dummy_packet;
+
         /* Network stack work  */
         struct work_struct netstack_work;