ath9k_htc: Protect RX stream variables

Use a spin lock to prevent concurrent access
to variables dealing with RX stream mode handling.
Currently, no protection is implemented - which
causes problems in RX.

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

2 files changed, 9 insertions, 0 deletions

diff --git a/drivers/net/wireless/ath/ath9k/hif_usb.c b/drivers/net/wireless/ath/ath9k/hif_usb.c
index 3afc747ccfbf..8838cdfcc497 100644
--- a/drivers/net/wireless/ath/ath9k/hif_usb.c
+++ b/drivers/net/wireless/ath/ath9k/hif_usb.c
@@ -330,6 +330,8 @@ static void ath9k_hif_usb_rx_stream(struct hif_device_usb *hif_dev,
         u16 pkt_len, pkt_tag, pool_index = 0;
         u8 *ptr;
 
+        spin_lock(&hif_dev->rx_lock);
+
         rx_remain_len = hif_dev->rx_remain_len;
         rx_pkt_len = hif_dev->rx_transfer_len;
 
@@ -356,6 +358,8 @@ static void ath9k_hif_usb_rx_stream(struct hif_device_usb *hif_dev,
                 }
         }
 
+        spin_unlock(&hif_dev->rx_lock);
+
         while (index < len) {
                 ptr = (u8 *) skb->data;
 
@@ -373,6 +377,7 @@ static void ath9k_hif_usb_rx_stream(struct hif_device_usb *hif_dev,
                         index = index + 4 + pkt_len + pad_len;
 
                         if (index > MAX_RX_BUF_SIZE) {
+                                spin_lock(&hif_dev->rx_lock);
                                 hif_dev->rx_remain_len = index - MAX_RX_BUF_SIZE;
                                 hif_dev->rx_transfer_len =
                                         MAX_RX_BUF_SIZE - chk_idx - 4;
@@ -384,6 +389,7 @@ static void ath9k_hif_usb_rx_stream(struct hif_device_usb *hif_dev,
                                         dev_err(&hif_dev->udev->dev,
                                         "ath9k_htc: RX memory allocation"
                                         " error\n");
+                                        spin_unlock(&hif_dev->rx_lock);
                                         goto err;
                                 }
                                 skb_reserve(nskb, 32);
@@ -394,6 +400,7 @@ static void ath9k_hif_usb_rx_stream(struct hif_device_usb *hif_dev,
 
                                 /* Record the buffer pointer */
                                 hif_dev->remain_skb = nskb;
+                                spin_unlock(&hif_dev->rx_lock);
                         } else {
                                 nskb = __dev_alloc_skb(pkt_len + 32, GFP_ATOMIC);
                                 if (!nskb) {
@@ -612,6 +619,7 @@ static int ath9k_hif_usb_alloc_rx_urbs(struct hif_device_usb *hif_dev)
         int i, ret;
 
         init_usb_anchor(&hif_dev->rx_submitted);
+        spin_lock_init(&hif_dev->rx_lock);
 
         for (i = 0; i < MAX_RX_URB_NUM; i++) {
 
diff --git a/drivers/net/wireless/ath/ath9k/hif_usb.h b/drivers/net/wireless/ath/ath9k/hif_usb.h
index ea9257bdc411..ed9708cd4aa0 100644
--- a/drivers/net/wireless/ath/ath9k/hif_usb.h
+++ b/drivers/net/wireless/ath/ath9k/hif_usb.h
@@ -93,6 +93,7 @@ struct hif_device_usb {
         int rx_pkt_len;
         int rx_transfer_len;
         int rx_pad_len;
+        spinlock_t rx_lock;
         u8 flags; /* HIF_USB_* */
 };