ath9k_htc: Simplify RX URB management

This patch introduces the usage of URB anchors,
thus reducing a large amount of code dealing with
URB maintenance within the driver. The RX callback now
takes care of freeing the SKB associated with each URB.

Signed-off-by: Sujith <Sujith.Manoharan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/ath/ath9k/hif_usb.c b/drivers/net/wireless/ath/ath9k/hif_usb.c
index fc4f6e8..e584a29 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/hif_usb.c
+++ b/drivers/net/wireless/ath/ath9k/hif_usb.c
@@ -299,6 +299,8 @@ static int hif_usb_send(void *hif_handle, u8 pipe_id, struct sk_buff *skb,
                ret = hif_usb_send_regout(hif_dev, skb);
                break;
        default:
+               dev_err(&hif_dev->udev->dev,
+                       "ath9k_htc: Invalid TX pipe: %d\n", pipe_id);
                ret = -EINVAL;
                break;
        }
@@ -408,14 +410,11 @@ static void ath9k_hif_usb_rx_stream(struct hif_device_usb *hif_dev,
                        }
                } else {
                        RX_STAT_INC(skb_dropped);
-                       dev_kfree_skb_any(skb);
                        return;
                }
        }
 
 err:
-       dev_kfree_skb_any(skb);
-
        for (i = 0; i < pool_index; i++) {
                ath9k_htc_rx_msg(hif_dev->htc_handle, skb_pool[i],
                                 skb_pool[i]->len, USB_WLAN_RX_PIPE);
@@ -426,11 +425,13 @@ err:
 static void ath9k_hif_usb_rx_cb(struct urb *urb)
 {
        struct sk_buff *skb = (struct sk_buff *) urb->context;
-       struct sk_buff *nskb;
        struct hif_device_usb *hif_dev = (struct hif_device_usb *)
                usb_get_intfdata(usb_ifnum_to_if(urb->dev, 0));
        int ret;
 
+       if (!skb)
+               return;
+
        if (!hif_dev)
                goto free;
 
@@ -448,34 +449,19 @@ static void ath9k_hif_usb_rx_cb(struct urb *urb)
 
        if (likely(urb->actual_length != 0)) {
                skb_put(skb, urb->actual_length);
-
-               nskb = __dev_alloc_skb(MAX_RX_BUF_SIZE, GFP_ATOMIC);
-               if (!nskb)
-                       goto resubmit;
-
-               usb_fill_bulk_urb(urb, hif_dev->udev,
-                                 usb_rcvbulkpipe(hif_dev->udev,
-                                                 USB_WLAN_RX_PIPE),
-                                 nskb->data, MAX_RX_BUF_SIZE,
-                                 ath9k_hif_usb_rx_cb, nskb);
-
-               ret = usb_submit_urb(urb, GFP_ATOMIC);
-               if (ret) {
-                       dev_kfree_skb_any(nskb);
-                       goto free;
-               }
-
                ath9k_hif_usb_rx_stream(hif_dev, skb);
-               return;
        }
 
 resubmit:
        skb_reset_tail_pointer(skb);
        skb_trim(skb, 0);
 
+       usb_anchor_urb(urb, &hif_dev->rx_submitted);
        ret = usb_submit_urb(urb, GFP_ATOMIC);
-       if (ret)
+       if (ret) {
+               usb_unanchor_urb(urb);
                goto free;
+       }
 
        return;
 free:
@@ -490,6 +476,9 @@ static void ath9k_hif_usb_reg_in_cb(struct urb *urb)
                usb_get_intfdata(usb_ifnum_to_if(urb->dev, 0));
        int ret;
 
+       if (!skb)
+               return;
+
        if (!hif_dev)
                goto free;
 
@@ -540,6 +529,7 @@ resubmit:
        return;
 free:
        dev_kfree_skb_any(skb);
+       urb->context = NULL;
 }
 
 static void ath9k_hif_usb_dealloc_tx_urbs(struct hif_device_usb *hif_dev)
@@ -609,78 +599,59 @@ err:
        return -ENOMEM;
 }
 
-static void ath9k_hif_usb_dealloc_rx_skbs(struct hif_device_usb *hif_dev)
-{
-       int i;
-
-       for (i = 0; i < MAX_RX_URB_NUM; i++) {
-               if (hif_dev->wlan_rx_data_urb[i]) {
-                       if (hif_dev->wlan_rx_data_urb[i]->transfer_buffer)
-                               dev_kfree_skb_any((void *)
-                                         hif_dev->wlan_rx_data_urb[i]->context);
-               }
-       }
-}
-
 static void ath9k_hif_usb_dealloc_rx_urbs(struct hif_device_usb *hif_dev)
 {
-       int i;
-
-       for (i = 0; i < MAX_RX_URB_NUM; i++) {
-               if (hif_dev->wlan_rx_data_urb[i]) {
-                       usb_kill_urb(hif_dev->wlan_rx_data_urb[i]);
-                       usb_free_urb(hif_dev->wlan_rx_data_urb[i]);
-                       hif_dev->wlan_rx_data_urb[i] = NULL;
-               }
-       }
-}
-
-static int ath9k_hif_usb_prep_rx_urb(struct hif_device_usb *hif_dev,
-                                    struct urb *urb)
-{
-       struct sk_buff *skb;
-
-       skb = __dev_alloc_skb(MAX_RX_BUF_SIZE, GFP_KERNEL);
-       if (!skb)
-               return -ENOMEM;
-
-       usb_fill_bulk_urb(urb, hif_dev->udev,
-                         usb_rcvbulkpipe(hif_dev->udev, USB_WLAN_RX_PIPE),
-                         skb->data, MAX_RX_BUF_SIZE,
-                         ath9k_hif_usb_rx_cb, skb);
-       return 0;
+       usb_kill_anchored_urbs(&hif_dev->rx_submitted);
 }
 
 static int ath9k_hif_usb_alloc_rx_urbs(struct hif_device_usb *hif_dev)
 {
+       struct urb *urb = NULL;
+       struct sk_buff *skb = NULL;
        int i, ret;
 
+       init_usb_anchor(&hif_dev->rx_submitted);
+
        for (i = 0; i < MAX_RX_URB_NUM; i++) {
 
                /* Allocate URB */
-               hif_dev->wlan_rx_data_urb[i] = usb_alloc_urb(0, GFP_KERNEL);
-               if (hif_dev->wlan_rx_data_urb[i] == NULL) {
+               urb = usb_alloc_urb(0, GFP_KERNEL);
+               if (urb == NULL) {
                        ret = -ENOMEM;
-                       goto err_rx_urb;
+                       goto err_urb;
                }
 
                /* Allocate buffer */
-               ret = ath9k_hif_usb_prep_rx_urb(hif_dev,
-                                               hif_dev->wlan_rx_data_urb[i]);
-               if (ret)
-                       goto err_rx_urb;
+               skb = __dev_alloc_skb(MAX_RX_BUF_SIZE, GFP_KERNEL);
+               if (!skb) {
+                       ret = -ENOMEM;
+                       goto err_skb;
+               }
 
-               /* Submit URB */
-               ret = usb_submit_urb(hif_dev->wlan_rx_data_urb[i], GFP_KERNEL);
-               if (ret)
-                       goto err_rx_urb;
+               usb_fill_bulk_urb(urb, hif_dev->udev,
+                                 usb_rcvbulkpipe(hif_dev->udev,
+                                                 USB_WLAN_RX_PIPE),
+                                 skb->data, MAX_RX_BUF_SIZE,
+                                 ath9k_hif_usb_rx_cb, skb);
 
+               /* Anchor URB */
+               usb_anchor_urb(urb, &hif_dev->rx_submitted);
+
+               /* Submit URB */
+               ret = usb_submit_urb(urb, GFP_KERNEL);
+               if (ret) {
+                       usb_unanchor_urb(urb);
+                       goto err_submit;
+               }
        }
 
        return 0;
 
-err_rx_urb:
-       ath9k_hif_usb_dealloc_rx_skbs(hif_dev);
+err_submit:
+       dev_kfree_skb_any(skb);
+err_skb:
+       usb_free_urb(urb);
+err_urb:
        ath9k_hif_usb_dealloc_rx_urbs(hif_dev);
        return ret;
 }
@@ -689,6 +660,8 @@ static void ath9k_hif_usb_dealloc_reg_in_urb(struct hif_device_usb *hif_dev)
 {
        if (hif_dev->reg_in_urb) {
                usb_kill_urb(hif_dev->reg_in_urb);
+               if (hif_dev->reg_in_urb->context)
+                       dev_kfree_skb_any((void *)hif_dev->reg_in_urb->context);
                usb_free_urb(hif_dev->reg_in_urb);
                hif_dev->reg_in_urb = NULL;
        }
@@ -712,12 +685,10 @@ static int ath9k_hif_usb_alloc_reg_in_urb(struct hif_device_usb *hif_dev)
                         ath9k_hif_usb_reg_in_cb, skb, 1);
 
        if (usb_submit_urb(hif_dev->reg_in_urb, GFP_KERNEL) != 0)
-               goto err_skb;
+               goto err;
 
        return 0;
 
-err_skb:
-       dev_kfree_skb_any(skb);
 err:
        ath9k_hif_usb_dealloc_reg_in_urb(hif_dev);
        return -ENOMEM;

diff --git a/drivers/net/wireless/ath/ath9k/hif_usb.h b/drivers/net/wireless/ath/ath9k/hif_usb.h
index 7cc3762..ea9257b 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/hif_usb.h
+++ b/drivers/net/wireless/ath/ath9k/hif_usb.h
@@ -85,18 +85,15 @@ struct hif_device_usb {
        struct usb_interface *interface;
        const struct firmware *firmware;
        struct htc_target *htc_handle;
-       u8 flags;
-
        struct hif_usb_tx tx;
-
-       struct urb *wlan_rx_data_urb[MAX_RX_URB_NUM];
        struct urb *reg_in_urb;
-
+       struct usb_anchor rx_submitted;
        struct sk_buff *remain_skb;
        int rx_remain_len;
        int rx_pkt_len;
        int rx_transfer_len;
        int rx_pad_len;
+       u8 flags; /* HIF_USB_* */
 };
 
 int ath9k_hif_usb_init(void);