rtlwifi: usb: defer rx processing to tasklet

Move processing of received packets to tasklet from hard-irq context.

Signed-off-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 51 insertions, 15 deletions

diff --git a/drivers/net/wireless/rtlwifi/rtl8192cu/trx.c b/drivers/net/wireless/rtlwifi/rtl8192cu/trx.c
index b6222eedb835..710f7904ecdf 100644
--- a/drivers/net/wireless/rtlwifi/rtl8192cu/trx.c
+++ b/drivers/net/wireless/rtlwifi/rtl8192cu/trx.c
@@ -434,7 +434,7 @@ static void _rtl_rx_process(struct ieee80211_hw *hw, struct sk_buff *skb)
                  (u32)hdr->addr1[2], (u32)hdr->addr1[3],
                  (u32)hdr->addr1[4], (u32)hdr->addr1[5]);
         memcpy(IEEE80211_SKB_RXCB(skb), rx_status, sizeof(*rx_status));
-        ieee80211_rx_irqsafe(hw, skb);
+        ieee80211_rx(hw, skb);
 }
 
 void  rtl8192cu_rx_hdl(struct ieee80211_hw *hw, struct sk_buff * skb)
diff --git a/drivers/net/wireless/rtlwifi/usb.c b/drivers/net/wireless/rtlwifi/usb.c
index 8df5836cc99c..a7b54f631293 100644
--- a/drivers/net/wireless/rtlwifi/usb.c
+++ b/drivers/net/wireless/rtlwifi/usb.c
@@ -308,6 +308,8 @@ static int _rtl_usb_init_tx(struct ieee80211_hw *hw)
         return 0;
 }
 
+static void _rtl_rx_work(unsigned long param);
+
 static int _rtl_usb_init_rx(struct ieee80211_hw *hw)
 {
         struct rtl_priv *rtlpriv = rtl_priv(hw);
@@ -325,6 +327,11 @@ static int _rtl_usb_init_rx(struct ieee80211_hw *hw)
                 rtlusb->rx_max_size, rtlusb->rx_urb_num, rtlusb->in_ep);
         init_usb_anchor(&rtlusb->rx_submitted);
         init_usb_anchor(&rtlusb->rx_cleanup_urbs);
+
+        skb_queue_head_init(&rtlusb->rx_queue);
+        rtlusb->rx_work_tasklet.func = _rtl_rx_work;
+        rtlusb->rx_work_tasklet.data = (unsigned long)rtlusb;
+
         return 0;
 }
 
@@ -515,7 +522,7 @@ static void _rtl_usb_rx_process_noagg(struct ieee80211_hw *hw,
                 }
 
                 if (likely(rtl_action_proc(hw, skb, false)))
-                        ieee80211_rx_irqsafe(hw, skb);
+                        ieee80211_rx(hw, skb);
                 else
                         dev_kfree_skb_any(skb);
         }
@@ -534,7 +541,31 @@ static void _rtl_rx_pre_process(struct ieee80211_hw *hw, struct sk_buff *skb)
         while (!skb_queue_empty(&rx_queue)) {
                 _skb = skb_dequeue(&rx_queue);
                 _rtl_usb_rx_process_agg(hw, _skb);
-                ieee80211_rx_irqsafe(hw, _skb);
+                ieee80211_rx(hw, _skb);
+        }
+}
+
+#define __RX_SKB_MAX_QUEUED     32
+
+static void _rtl_rx_work(unsigned long param)
+{
+        struct rtl_usb *rtlusb = (struct rtl_usb *)param;
+        struct ieee80211_hw *hw = usb_get_intfdata(rtlusb->intf);
+        struct sk_buff *skb;
+
+        while ((skb = skb_dequeue(&rtlusb->rx_queue))) {
+                if (unlikely(IS_USB_STOP(rtlusb))) {
+                        dev_kfree_skb_any(skb);
+                        continue;
+                }
+
+                if (likely(!rtlusb->usb_rx_segregate_hdl)) {
+                        _rtl_usb_rx_process_noagg(hw, skb);
+                } else {
+                        /* TO DO */
+                        _rtl_rx_pre_process(hw, skb);
+                        pr_err("rx agg not supported\n");
+                }
         }
 }
 
@@ -552,6 +583,7 @@ static void _rtl_rx_completed(struct urb *_urb)
 
         if (likely(0 == _urb->status)) {
                 struct sk_buff *skb;
+                unsigned int qlen;
                 unsigned int size = _urb->actual_length;
 
                 if (size < RTL_RX_DESC_SIZE + sizeof(struct ieee80211_hdr)) {
@@ -561,6 +593,14 @@ static void _rtl_rx_completed(struct urb *_urb)
                         goto resubmit;
                 }
 
+                qlen = skb_queue_len(&rtlusb->rx_queue);
+                if (qlen >= __RX_SKB_MAX_QUEUED) {
+                        RT_TRACE(rtlpriv, COMP_USB, DBG_EMERG,
+                                 "Pending RX skbuff queue full! (qlen: %d)\n",
+                                 qlen);
+                        goto resubmit;
+                }
+
                 skb = dev_alloc_skb(size + __RADIO_TAP_SIZE_RSV);
                 if (!skb) {
                         RT_TRACE(rtlpriv, COMP_USB, DBG_EMERG,
@@ -575,17 +615,8 @@ static void _rtl_rx_completed(struct urb *_urb)
 
                 memcpy(skb_put(skb, size), _urb->transfer_buffer, size);
 
-                /* TODO: Do further processing in tasklet (queue skbs,
-                 * schedule tasklet)
-                 */
-
-                if (likely(!rtlusb->usb_rx_segregate_hdl)) {
-                        _rtl_usb_rx_process_noagg(hw, skb);
-                } else {
-                        /* TO DO */
-                        _rtl_rx_pre_process(hw, skb);
-                        pr_err("rx agg not supported\n");
-                }
+                skb_queue_tail(&rtlusb->rx_queue, skb);
+                tasklet_schedule(&rtlusb->rx_work_tasklet);
 
                 goto resubmit;
         }
@@ -626,6 +657,9 @@ static void _rtl_usb_cleanup_rx(struct ieee80211_hw *hw)
 
         usb_kill_anchored_urbs(&rtlusb->rx_submitted);
 
+        tasklet_kill(&rtlusb->rx_work_tasklet);
+        skb_queue_purge(&rtlusb->rx_queue);
+
         while ((urb = usb_get_from_anchor(&rtlusb->rx_cleanup_urbs))) {
                 usb_free_coherent(urb->dev, urb->transfer_buffer_length,
                                 urb->transfer_buffer, urb->transfer_dma);
diff --git a/drivers/net/wireless/rtlwifi/usb.h b/drivers/net/wireless/rtlwifi/usb.h
index 22d7c68258ec..685273ca9561 100644
--- a/drivers/net/wireless/rtlwifi/usb.h
+++ b/drivers/net/wireless/rtlwifi/usb.h
@@ -136,12 +136,14 @@ struct rtl_usb {
         void (*usb_tx_cleanup)(struct ieee80211_hw *, struct sk_buff *);
 
         /* Rx */
-        u8 in_ep_nums ;
+        u8 in_ep_nums;
         u32 in_ep;              /* Bulk IN endpoint number */
         u32 rx_max_size;        /* Bulk IN max buffer size */
         u32 rx_urb_num;         /* How many Bulk INs are submitted to host. */
         struct usb_anchor       rx_submitted;
         struct usb_anchor       rx_cleanup_urbs;
+        struct tasklet_struct   rx_work_tasklet;
+        struct sk_buff_head     rx_queue;
         void (*usb_rx_segregate_hdl)(struct ieee80211_hw *, struct sk_buff *,
                                      struct sk_buff_head *);
         void (*usb_rx_hdl)(struct ieee80211_hw *, struct sk_buff *);