10 files changed, 141 insertions, 59 deletions

diff --git a/drivers/net/wireless/ath/ar9170/Kconfig b/drivers/net/wireless/ath/ar9170/Kconfig
index 05918f1e685a..d7a4799d20fb 100644
--- a/drivers/net/wireless/ath/ar9170/Kconfig
+++ b/drivers/net/wireless/ath/ar9170/Kconfig
@@ -1,6 +1,6 @@
 config AR9170_USB
         tristate "Atheros AR9170 802.11n USB support"
-        depends on USB && MAC80211 && WLAN_80211
+        depends on USB && MAC80211
         select FW_LOADER
         help
           This is a driver for the Atheros "otus" 802.11n USB devices.
diff --git a/drivers/net/wireless/ath/ar9170/ar9170.h b/drivers/net/wireless/ath/ar9170/ar9170.h
index 914e4718a9a8..9f9459860d82 100644
--- a/drivers/net/wireless/ath/ar9170/ar9170.h
+++ b/drivers/net/wireless/ath/ar9170/ar9170.h
@@ -172,8 +172,6 @@ struct ar9170 {
 
         /* interface mode settings */
         struct ieee80211_vif *vif;
-        u8 mac_addr[ETH_ALEN];
-        u8 bssid[ETH_ALEN];
 
         /* beaconing */
         struct sk_buff *beacon;
@@ -204,6 +202,8 @@ struct ar9170 {
         u8 power_2G_ht20[8];
         u8 power_2G_ht40[8];
 
+        u8 phy_heavy_clip;
+
 #ifdef CONFIG_AR9170_LEDS
         struct delayed_work led_work;
         struct ar9170_led leds[AR9170_NUM_LEDS];
@@ -231,7 +231,7 @@ struct ar9170 {
         struct sk_buff_head tx_status_ampdu;
         spinlock_t tx_ampdu_list_lock;
         struct list_head tx_ampdu_list;
-        unsigned int tx_ampdu_pending;
+        atomic_t tx_ampdu_pending;
 
         /* rxstream mpdu merge */
         struct ar9170_rxstream_mpdu_merge rx_mpdu;
diff --git a/drivers/net/wireless/ath/ar9170/cmd.c b/drivers/net/wireless/ath/ar9170/cmd.c
index f57a6200167b..cf6f5c4174a6 100644
--- a/drivers/net/wireless/ath/ar9170/cmd.c
+++ b/drivers/net/wireless/ath/ar9170/cmd.c
@@ -72,8 +72,7 @@ int ar9170_write_reg(struct ar9170 *ar, const u32 reg, const u32 val)
         return err;
 }
 
-static int ar9170_read_mreg(struct ar9170 *ar, int nregs,
-                            const u32 *regs, u32 *out)
+int ar9170_read_mreg(struct ar9170 *ar, int nregs, const u32 *regs, u32 *out)
 {
         int i, err;
         __le32 *offs, *res;
diff --git a/drivers/net/wireless/ath/ar9170/cmd.h b/drivers/net/wireless/ath/ar9170/cmd.h
index a4f0e50e52b4..826c45e6b274 100644
--- a/drivers/net/wireless/ath/ar9170/cmd.h
+++ b/drivers/net/wireless/ath/ar9170/cmd.h
@@ -44,6 +44,7 @@
 int ar9170_write_mem(struct ar9170 *ar, const __le32 *data, size_t len);
 int ar9170_write_reg(struct ar9170 *ar, const u32 reg, const u32 val);
 int ar9170_read_reg(struct ar9170 *ar, u32 reg, u32 *val);
+int ar9170_read_mreg(struct ar9170 *ar, int nregs, const u32 *regs, u32 *out);
 int ar9170_echo_test(struct ar9170 *ar, u32 v);
 
 /*
diff --git a/drivers/net/wireless/ath/ar9170/hw.h b/drivers/net/wireless/ath/ar9170/hw.h
index 6cbfb2f83391..701ddb7d8400 100644
--- a/drivers/net/wireless/ath/ar9170/hw.h
+++ b/drivers/net/wireless/ath/ar9170/hw.h
@@ -152,14 +152,14 @@ enum ar9170_cmd {
 #define         AR9170_MAC_REG_FTF_BIT14                BIT(14)
 #define         AR9170_MAC_REG_FTF_BIT15                BIT(15)
 #define         AR9170_MAC_REG_FTF_BAR                  BIT(24)
-#define         AR9170_MAC_REG_FTF_BIT25                BIT(25)
+#define         AR9170_MAC_REG_FTF_BA                   BIT(25)
 #define         AR9170_MAC_REG_FTF_PSPOLL               BIT(26)
 #define         AR9170_MAC_REG_FTF_RTS                  BIT(27)
 #define         AR9170_MAC_REG_FTF_CTS                  BIT(28)
 #define         AR9170_MAC_REG_FTF_ACK                  BIT(29)
 #define         AR9170_MAC_REG_FTF_CFE                  BIT(30)
 #define         AR9170_MAC_REG_FTF_CFE_ACK              BIT(31)
-#define         AR9170_MAC_REG_FTF_DEFAULTS             0x0500ffff
+#define         AR9170_MAC_REG_FTF_DEFAULTS             0x0700ffff
 #define         AR9170_MAC_REG_FTF_MONITOR              0xfd00ffff
 
 #define AR9170_MAC_REG_RX_TOTAL                 (AR9170_MAC_REG_BASE + 0x6A0)
@@ -311,6 +311,8 @@ struct ar9170_tx_control {
 
 #define AR9170_TX_PHY_SHORT_GI                  0x80000000
 
+#define AR5416_MAX_RATE_POWER                   63
+
 struct ar9170_rx_head {
         u8 plcp[12];
 } __packed;
diff --git a/drivers/net/wireless/ath/ar9170/mac.c b/drivers/net/wireless/ath/ar9170/mac.c
index 614e3218a2bc..ddc8c09dc79e 100644
--- a/drivers/net/wireless/ath/ar9170/mac.c
+++ b/drivers/net/wireless/ath/ar9170/mac.c
@@ -35,6 +35,9 @@
  *    ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  *    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
+
+#include <asm/unaligned.h>
+
 #include "ar9170.h"
 #include "cmd.h"
 
@@ -227,11 +230,8 @@ static int ar9170_set_mac_reg(struct ar9170 *ar, const u32 reg, const u8 *mac)
 
         ar9170_regwrite_begin(ar);
 
-        ar9170_regwrite(reg,
-                        (mac[3] << 24) | (mac[2] << 16) |
-                        (mac[1] << 8) | mac[0]);
-
-        ar9170_regwrite(reg + 4, (mac[5] << 8) | mac[4]);
+        ar9170_regwrite(reg, get_unaligned_le32(mac));
+        ar9170_regwrite(reg + 4, get_unaligned_le16(mac + 4));
 
         ar9170_regwrite_finish();
 
@@ -311,13 +311,14 @@ static int ar9170_set_promiscouous(struct ar9170 *ar)
 
 int ar9170_set_operating_mode(struct ar9170 *ar)
 {
+        struct ath_common *common = &ar->common;
         u32 pm_mode = AR9170_MAC_REG_POWERMGT_DEFAULTS;
         u8 *mac_addr, *bssid;
         int err;
 
         if (ar->vif) {
-                mac_addr = ar->mac_addr;
-                bssid = ar->bssid;
+                mac_addr = common->macaddr;
+                bssid = common->curbssid;
 
                 switch (ar->vif->type) {
                 case NL80211_IFTYPE_MESH_POINT:
diff --git a/drivers/net/wireless/ath/ar9170/main.c b/drivers/net/wireless/ath/ar9170/main.c
index c1f8c69db165..f9d6db8d013e 100644
--- a/drivers/net/wireless/ath/ar9170/main.c
+++ b/drivers/net/wireless/ath/ar9170/main.c
@@ -414,9 +414,9 @@ static void ar9170_tx_ampdu_callback(struct ar9170 *ar, struct sk_buff *skb)
 
         skb_queue_tail(&ar->tx_status_ampdu, skb);
         ar9170_tx_fake_ampdu_status(ar);
-        ar->tx_ampdu_pending--;
 
-        if (!list_empty(&ar->tx_ampdu_list) && !ar->tx_ampdu_pending)
+        if (atomic_dec_and_test(&ar->tx_ampdu_pending) &&
+            !list_empty(&ar->tx_ampdu_list))
                 ar9170_tx_ampdu(ar);
 }
 
@@ -850,6 +850,7 @@ static int ar9170_rx_mac_status(struct ar9170 *ar,
                 }
                 break;
 
+        case AR9170_RX_STATUS_MODULATION_DUPOFDM:
         case AR9170_RX_STATUS_MODULATION_OFDM:
                 switch (head->plcp[0] & 0xf) {
                 case 0xb:
@@ -897,8 +898,7 @@ static int ar9170_rx_mac_status(struct ar9170 *ar,
                 status->flag |= RX_FLAG_HT;
                 break;
 
-        case AR9170_RX_STATUS_MODULATION_DUPOFDM:
-                /* XXX */
+        default:
                 if (ar9170_nag_limiter(ar))
                         printk(KERN_ERR "%s: invalid modulation\n",
                                wiphy_name(ar->hw->wiphy));
@@ -1248,6 +1248,7 @@ static int ar9170_op_start(struct ieee80211_hw *hw)
         ar->global_ampdu_density = 6;
         ar->global_ampdu_factor = 3;
 
+        atomic_set(&ar->tx_ampdu_pending, 0);
         ar->bad_hw_nagger = jiffies;
 
         err = ar->open(ar);
@@ -1773,7 +1774,7 @@ static void ar9170_tx(struct ar9170 *ar)
                                           msecs_to_jiffies(AR9170_TX_TIMEOUT);
 
                         if (arinfo->flags == AR9170_TX_FLAG_BLOCK_ACK)
-                                ar->tx_ampdu_pending++;
+                                atomic_inc(&ar->tx_ampdu_pending);
 
 #ifdef AR9170_QUEUE_DEBUG
                         printk(KERN_DEBUG "%s: send frame q:%d =>\n",
@@ -1784,7 +1785,7 @@ static void ar9170_tx(struct ar9170 *ar)
                         err = ar->tx(ar, skb);
                         if (unlikely(err)) {
                                 if (arinfo->flags == AR9170_TX_FLAG_BLOCK_ACK)
-                                        ar->tx_ampdu_pending--;
+                                        atomic_dec(&ar->tx_ampdu_pending);
 
                                 frames_failed++;
                                 dev_kfree_skb_any(skb);
@@ -1931,7 +1932,7 @@ int ar9170_op_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
         if (info->flags & IEEE80211_TX_CTL_AMPDU) {
                 bool run = ar9170_tx_ampdu_queue(ar, skb);
 
-                if (run || !ar->tx_ampdu_pending)
+                if (run || !atomic_read(&ar->tx_ampdu_pending))
                         ar9170_tx_ampdu(ar);
         } else {
                 unsigned int queue = skb_get_queue_mapping(skb);
@@ -1952,6 +1953,7 @@ static int ar9170_op_add_interface(struct ieee80211_hw *hw,
                                    struct ieee80211_if_init_conf *conf)
 {
         struct ar9170 *ar = hw->priv;
+        struct ath_common *common = &ar->common;
         int err = 0;
 
         mutex_lock(&ar->mutex);
@@ -1962,7 +1964,7 @@ static int ar9170_op_add_interface(struct ieee80211_hw *hw,
         }
 
         ar->vif = conf->vif;
-        memcpy(ar->mac_addr, conf->mac_addr, ETH_ALEN);
+        memcpy(common->macaddr, conf->mac_addr, ETH_ALEN);
 
         if (modparam_nohwcrypt || (ar->vif->type != NL80211_IFTYPE_STATION)) {
                 ar->rx_software_decryption = true;
@@ -2131,12 +2133,13 @@ static void ar9170_op_bss_info_changed(struct ieee80211_hw *hw,
                                        u32 changed)
 {
         struct ar9170 *ar = hw->priv;
+        struct ath_common *common = &ar->common;
         int err = 0;
 
         mutex_lock(&ar->mutex);
 
         if (changed & BSS_CHANGED_BSSID) {
-                memcpy(ar->bssid, bss_conf->bssid, ETH_ALEN);
+                memcpy(common->curbssid, bss_conf->bssid, ETH_ALEN);
                 err = ar9170_set_operating_mode(ar);
                 if (err)
                         goto out;
@@ -2190,22 +2193,30 @@ static u64 ar9170_op_get_tsf(struct ieee80211_hw *hw)
 {
         struct ar9170 *ar = hw->priv;
         int err;
-        u32 tsf_low;
-        u32 tsf_high;
         u64 tsf;
+#define NR 3
+        static const u32 addr[NR] = { AR9170_MAC_REG_TSF_H,
+                                    AR9170_MAC_REG_TSF_L,
+                                    AR9170_MAC_REG_TSF_H };
+        u32 val[NR];
+        int loops = 0;
 
         mutex_lock(&ar->mutex);
-        err = ar9170_read_reg(ar, AR9170_MAC_REG_TSF_L, &tsf_low);
-        if (!err)
-                err = ar9170_read_reg(ar, AR9170_MAC_REG_TSF_H, &tsf_high);
+
+        while (loops++ < 10) {
+                err = ar9170_read_mreg(ar, NR, addr, val);
+                if (err || val[0] == val[2])
+                        break;
+        }
+
         mutex_unlock(&ar->mutex);
 
         if (WARN_ON(err))
                 return 0;
-
-        tsf = tsf_high;
-        tsf = (tsf << 32) | tsf_low;
+        tsf = val[0];
+        tsf = (tsf << 32) | val[1];
         return tsf;
+#undef NR
 }
 
 static int ar9170_set_key(struct ieee80211_hw *hw, enum set_key_cmd cmd,
@@ -2430,6 +2441,7 @@ static int ar9170_conf_tx(struct ieee80211_hw *hw, u16 queue,
 }
 
 static int ar9170_ampdu_action(struct ieee80211_hw *hw,
+                               struct ieee80211_vif *vif,
                                enum ieee80211_ampdu_mlme_action action,
                                struct ieee80211_sta *sta, u16 tid, u16 *ssn)
 {
@@ -2459,7 +2471,7 @@ static int ar9170_ampdu_action(struct ieee80211_hw *hw,
                 tid_info->state = AR9170_TID_STATE_PROGRESS;
                 tid_info->active = false;
                 spin_unlock_irqrestore(&ar->tx_ampdu_list_lock, flags);
-                ieee80211_start_tx_ba_cb_irqsafe(hw, sta->addr, tid);
+                ieee80211_start_tx_ba_cb_irqsafe(vif, sta->addr, tid);
                 break;
 
         case IEEE80211_AMPDU_TX_STOP:
@@ -2469,7 +2481,7 @@ static int ar9170_ampdu_action(struct ieee80211_hw *hw,
                 tid_info->active = false;
                 skb_queue_purge(&tid_info->queue);
                 spin_unlock_irqrestore(&ar->tx_ampdu_list_lock, flags);
-                ieee80211_stop_tx_ba_cb_irqsafe(hw, sta->addr, tid);
+                ieee80211_stop_tx_ba_cb_irqsafe(vif, sta->addr, tid);
                 break;
 
         case IEEE80211_AMPDU_TX_OPERATIONAL:
diff --git a/drivers/net/wireless/ath/ar9170/phy.c b/drivers/net/wireless/ath/ar9170/phy.c
index dbd488da18b1..45a415ea809a 100644
--- a/drivers/net/wireless/ath/ar9170/phy.c
+++ b/drivers/net/wireless/ath/ar9170/phy.c
@@ -1239,9 +1239,6 @@ static u8 ar9170_get_max_edge_power(struct ar9170 *ar,
                                     struct ar9170_calctl_edges edges[],
                                     u32 freq)
 {
-/* TODO: move somewhere else */
-#define AR5416_MAX_RATE_POWER        63
-
         int i;
         u8 rc = AR5416_MAX_RATE_POWER;
         u8 f;
@@ -1259,10 +1256,11 @@ static u8 ar9170_get_max_edge_power(struct ar9170 *ar,
                         break;
                 }
                 if (i > 0 && f < edges[i].channel) {
-                        if (f > edges[i-1].channel &&
-                            edges[i-1].power_flags & AR9170_CALCTL_EDGE_FLAGS) {
+                        if (f > edges[i - 1].channel &&
+                            edges[i - 1].power_flags &
+                            AR9170_CALCTL_EDGE_FLAGS) {
                                 /* lower channel has the inband flag set */
-                                rc = edges[i-1].power_flags &
+                                rc = edges[i - 1].power_flags &
                                         ~AR9170_CALCTL_EDGE_FLAGS;
                         }
                         break;
@@ -1270,18 +1268,48 @@ static u8 ar9170_get_max_edge_power(struct ar9170 *ar,
         }
 
         if (i == AR5416_NUM_BAND_EDGES) {
-                if (f > edges[i-1].channel &&
-                    edges[i-1].power_flags & AR9170_CALCTL_EDGE_FLAGS) {
+                if (f > edges[i - 1].channel &&
+                    edges[i - 1].power_flags & AR9170_CALCTL_EDGE_FLAGS) {
                         /* lower channel has the inband flag set */
-                        rc = edges[i-1].power_flags &
+                        rc = edges[i - 1].power_flags &
                                 ~AR9170_CALCTL_EDGE_FLAGS;
                 }
         }
         return rc;
 }
 
-/* calculate the conformance test limits and apply them to ar->power*
- * (derived from otus hal/hpmain.c, line 3706 ff.)
+static u8 ar9170_get_heavy_clip(struct ar9170 *ar,
+                                struct ar9170_calctl_edges edges[],
+                                u32 freq, enum ar9170_bw bw)
+{
+        u8 f;
+        int i;
+        u8 rc = 0;
+
+        if (freq < 3000)
+                f = freq - 2300;
+        else
+                f = (freq - 4800) / 5;
+
+        if (bw == AR9170_BW_40_BELOW || bw == AR9170_BW_40_ABOVE)
+                rc |= 0xf0;
+
+        for (i = 0; i < AR5416_NUM_BAND_EDGES; i++) {
+                if (edges[i].channel == 0xff)
+                        break;
+                if (f == edges[i].channel) {
+                        if (!(edges[i].power_flags & AR9170_CALCTL_EDGE_FLAGS))
+                                rc |= 0x0f;
+                        break;
+                }
+        }
+
+        return rc;
+}
+
+/*
+ * calculate the conformance test limits and the heavy clip parameter
+ * and apply them to ar->power* (derived from otus hal/hpmain.c, line 3706)
  */
 static void ar9170_calc_ctl(struct ar9170 *ar, u32 freq, enum ar9170_bw bw)
 {
@@ -1295,7 +1323,8 @@ static void ar9170_calc_ctl(struct ar9170 *ar, u32 freq, enum ar9170_bw bw)
                 int pwr_cal_len;
         } *modes;
 
-        /* order is relevant in the mode_list_*: we fall back to the
+        /*
+         * order is relevant in the mode_list_*: we fall back to the
          * lower indices if any mode is missed in the EEPROM.
          */
         struct ctl_modes mode_list_2ghz[] = {
@@ -1313,7 +1342,10 @@ static void ar9170_calc_ctl(struct ar9170 *ar, u32 freq, enum ar9170_bw bw)
 
 #define EDGES(c, n) (ar->eeprom.ctl_data[c].control_edges[n])
 
-        /* TODO: investigate the differences between OTUS'
+        ar->phy_heavy_clip = 0;
+
+        /*
+         * TODO: investigate the differences between OTUS'
          * hpreg.c::zfHpGetRegulatoryDomain() and
          * ath/regd.c::ath_regd_get_band_ctl() -
          * e.g. for FCC3_WORLD the OTUS procedure
@@ -1347,6 +1379,15 @@ static void ar9170_calc_ctl(struct ar9170 *ar, u32 freq, enum ar9170_bw bw)
                 if (ctl_idx < AR5416_NUM_CTLS) {
                         int f_off = 0;
 
+                        /* determine heav clip parameter from
+                           the 11G edges array */
+                        if (modes[i].ctl_mode == CTL_11G) {
+                                ar->phy_heavy_clip =
+                                        ar9170_get_heavy_clip(ar,
+                                                              EDGES(ctl_idx, 1),
+                                                              freq, bw);
+                        }
+
                         /* adjust freq for 40MHz */
                         if (modes[i].ctl_mode == CTL_2GHT40 ||
                             modes[i].ctl_mode == CTL_5GHT40) {
@@ -1360,13 +1401,15 @@ static void ar9170_calc_ctl(struct ar9170 *ar, u32 freq, enum ar9170_bw bw)
                                 ar9170_get_max_edge_power(ar, EDGES(ctl_idx, 1),
                                                           freq+f_off);
 
-                        /* TODO: check if the regulatory max. power is
+                        /*
+                         * TODO: check if the regulatory max. power is
                          *  controlled by cfg80211 for DFS
                          * (hpmain applies it to max_power itself for DFS freq)
                          */
 
                 } else {
-                        /* Workaround in otus driver, hpmain.c, line 3906:
+                        /*
+                         * Workaround in otus driver, hpmain.c, line 3906:
                          * if no data for 5GHT20 are found, take the
                          * legacy 5G value.
                          * We extend this here to fallback from any other *HT or
@@ -1390,6 +1433,19 @@ static void ar9170_calc_ctl(struct ar9170 *ar, u32 freq, enum ar9170_bw bw)
                                                        modes[i].max_power);
                 }
         }
+
+        if (ar->phy_heavy_clip & 0xf0) {
+                ar->power_2G_ht40[0]--;
+                ar->power_2G_ht40[1]--;
+                ar->power_2G_ht40[2]--;
+        }
+        if (ar->phy_heavy_clip & 0xf) {
+                ar->power_2G_ht20[0]++;
+                ar->power_2G_ht20[1]++;
+                ar->power_2G_ht20[2]++;
+        }
+
+
 #undef EDGES
 }
 
@@ -1499,8 +1555,6 @@ static int ar9170_set_power_cal(struct ar9170 *ar, u32 freq, enum ar9170_bw bw)
         /* calc. conformance test limits and apply to ar->power*[] */
         ar9170_calc_ctl(ar, freq, bw);
 
-        /* TODO: (heavy clip) regulatory domain power level fine-tuning. */
-
         /* set ACK/CTS TX power */
         ar9170_regwrite_begin(ar);
 
@@ -1643,6 +1697,17 @@ int ar9170_set_channel(struct ar9170 *ar, struct ieee80211_channel *channel,
         if (err)
                 return err;
 
+        if (ar->phy_heavy_clip) {
+                err = ar9170_write_reg(ar, 0x1c59e0,
+                                       0x200 | ar->phy_heavy_clip);
+                if (err) {
+                        if (ar9170_nag_limiter(ar))
+                                printk(KERN_ERR "%s: failed to set "
+                                       "heavy clip\n",
+                                       wiphy_name(ar->hw->wiphy));
+                }
+        }
+
         for (i = 0; i < 2; i++) {
                 ar->noise[i] = ar9170_calc_noise_dbm(
                                 (le32_to_cpu(vals[2 + i]) >> 19) & 0x1ff);
diff --git a/drivers/net/wireless/ath/ar9170/usb.c b/drivers/net/wireless/ath/ar9170/usb.c
index e974e5829e1a..e0799d924057 100644
--- a/drivers/net/wireless/ath/ar9170/usb.c
+++ b/drivers/net/wireless/ath/ar9170/usb.c
@@ -68,8 +68,10 @@ static struct usb_device_id ar9170_usb_ids[] = {
         { USB_DEVICE(0x0cf3, 0x1002) },
         /* Cace Airpcap NX */
         { USB_DEVICE(0xcace, 0x0300) },
-        /* D-Link DWA 160A */
+        /* D-Link DWA 160 A1 */
         { USB_DEVICE(0x07d1, 0x3c10) },
+        /* D-Link DWA 160 A2 */
+        { USB_DEVICE(0x07d1, 0x3a09) },
         /* Netgear WNDA3100 */
         { USB_DEVICE(0x0846, 0x9010) },
         /* Netgear WN111 v2 */
@@ -108,15 +110,15 @@ static void ar9170_usb_submit_urb(struct ar9170_usb *aru)
                 return ;
 
         spin_lock_irqsave(&aru->tx_urb_lock, flags);
-        if (aru->tx_submitted_urbs >= AR9170_NUM_TX_URBS) {
+        if (atomic_read(&aru->tx_submitted_urbs) >= AR9170_NUM_TX_URBS) {
                 spin_unlock_irqrestore(&aru->tx_urb_lock, flags);
                 return ;
         }
-        aru->tx_submitted_urbs++;
+        atomic_inc(&aru->tx_submitted_urbs);
 
         urb = usb_get_from_anchor(&aru->tx_pending);
         if (!urb) {
-                aru->tx_submitted_urbs--;
+                atomic_dec(&aru->tx_submitted_urbs);
                 spin_unlock_irqrestore(&aru->tx_urb_lock, flags);
 
                 return ;
@@ -133,7 +135,7 @@ static void ar9170_usb_submit_urb(struct ar9170_usb *aru)
                                 err);
 
                 usb_unanchor_urb(urb);
-                aru->tx_submitted_urbs--;
+                atomic_dec(&aru->tx_submitted_urbs);
                 ar9170_tx_callback(&aru->common, urb->context);
         }
 
@@ -151,7 +153,7 @@ static void ar9170_usb_tx_urb_complete_frame(struct urb *urb)
                 return ;
         }
 
-        aru->tx_submitted_urbs--;
+        atomic_dec(&aru->tx_submitted_urbs);
 
         ar9170_tx_callback(&aru->common, skb);
 
@@ -794,7 +796,7 @@ static int ar9170_usb_probe(struct usb_interface *intf,
         spin_lock_init(&aru->tx_urb_lock);
 
         aru->tx_pending_urbs = 0;
-        aru->tx_submitted_urbs = 0;
+        atomic_set(&aru->tx_submitted_urbs, 0);
 
         aru->common.stop = ar9170_usb_stop;
         aru->common.flush = ar9170_usb_flush;
diff --git a/drivers/net/wireless/ath/ar9170/usb.h b/drivers/net/wireless/ath/ar9170/usb.h
index d098f4d5d2f2..a2ce3b169ceb 100644
--- a/drivers/net/wireless/ath/ar9170/usb.h
+++ b/drivers/net/wireless/ath/ar9170/usb.h
@@ -67,7 +67,7 @@ struct ar9170_usb {
         bool req_one_stage_fw;
 
         spinlock_t tx_urb_lock;
-        unsigned int tx_submitted_urbs;
+        atomic_t tx_submitted_urbs;
         unsigned int tx_pending_urbs;
 
         struct completion cmd_wait;