b43: Remove TX spinlock

This removes the TX spinlock and defers TX to a workqueue to allow
locking wl->mutex instead and to allow sleeping for register accesses.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Tested-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/b43/b43.h b/drivers/net/wireless/b43/b43.h
index d63af926d058593ae4017f5cea95cc70e0c40522..1cd470d6e2da6a950bf04b45b9d47971bcd21baf 100644 (file)
--- a/drivers/net/wireless/b43/b43.h
+++ b/drivers/net/wireless/b43/b43.h
@@ -683,6 +683,11 @@ struct b43_wl {
         * This is scheduled when we determine that the actual TX output
         * power doesn't match what we want. */
        struct work_struct txpower_adjust_work;
+
+       /* Packet transmit work */
+       struct work_struct tx_work;
+       /* Queue of packets to be transmitted. */
+       struct sk_buff_head tx_queue;
 };
 
 /* The type of the firmware file. */

diff --git a/drivers/net/wireless/b43/main.c b/drivers/net/wireless/b43/main.c
index 80b688441ffe83eb06901e42c24b92fe07215cb3..fca2fe947d7d80874011c58b6fb6d2359cda0d59 100644 (file)
--- a/drivers/net/wireless/b43/main.c
+++ b/drivers/net/wireless/b43/main.c
@@ -690,7 +690,6 @@ static void b43_short_slot_timing_disable(struct b43_wldev *dev)
  */
 void b43_dummy_transmission(struct b43_wldev *dev, bool ofdm, bool pa_on)
 {
-       struct b43_wl *wl = dev->wl;
        struct b43_phy *phy = &dev->phy;
        unsigned int i, max_loop;
        u16 value;
@@ -710,8 +709,6 @@ void b43_dummy_transmission(struct b43_wldev *dev, bool ofdm, bool pa_on)
                buffer[0] = 0x000B846E;
        }
 
-       write_lock_irq(&wl->tx_lock);
-
        for (i = 0; i < 5; i++)
                b43_ram_write(dev, i * 4, buffer[i]);
 
@@ -767,8 +764,6 @@ void b43_dummy_transmission(struct b43_wldev *dev, bool ofdm, bool pa_on)
        }
        if (phy->radio_ver == 0x2050 && phy->radio_rev <= 0x5)
                b43_radio_write16(dev, 0x0051, 0x0037);
-
-       write_unlock_irq(&wl->tx_lock);
 }
 
 static void key_write(struct b43_wldev *dev,
@@ -3098,42 +3093,49 @@ static int b43_rng_init(struct b43_wl *wl)
        return err;
 }
 
-static int b43_op_tx(struct ieee80211_hw *hw,
-                    struct sk_buff *skb)
+static void b43_tx_work(struct work_struct *work)
 {
-       struct b43_wl *wl = hw_to_b43_wl(hw);
-       struct b43_wldev *dev = wl->current_dev;
-       unsigned long flags;
-       int err;
+       struct b43_wl *wl = container_of(work, struct b43_wl, tx_work);
+       struct b43_wldev *dev;
+       struct sk_buff *skb;
+       int err = 0;
 
-       if (unlikely(skb->len < 2 + 2 + 6)) {
-               /* Too short, this can't be a valid frame. */
-               goto drop_packet;
+       mutex_lock(&wl->mutex);
+       dev = wl->current_dev;
+       if (unlikely(!dev || b43_status(dev) < B43_STAT_STARTED)) {
+               mutex_unlock(&wl->mutex);
+               return;
        }
-       B43_WARN_ON(skb_shinfo(skb)->nr_frags);
-       if (unlikely(!dev))
-               goto drop_packet;
 
-       /* Transmissions on seperate queues can run concurrently. */
-       read_lock_irqsave(&wl->tx_lock, flags);
+       while (skb_queue_len(&wl->tx_queue)) {
+               skb = skb_dequeue(&wl->tx_queue);
 
-       err = -ENODEV;
-       if (likely(b43_status(dev) >= B43_STAT_STARTED)) {
                if (b43_using_pio_transfers(dev))
                        err = b43_pio_tx(dev, skb);
                else
                        err = b43_dma_tx(dev, skb);
+               if (unlikely(err))
+                       dev_kfree_skb(skb); /* Drop it */
        }
 
-       read_unlock_irqrestore(&wl->tx_lock, flags);
+       mutex_unlock(&wl->mutex);
+}
 
-       if (unlikely(err))
-               goto drop_packet;
-       return NETDEV_TX_OK;
+static int b43_op_tx(struct ieee80211_hw *hw,
+                    struct sk_buff *skb)
+{
+       struct b43_wl *wl = hw_to_b43_wl(hw);
+
+       if (unlikely(skb->len < 2 + 2 + 6)) {
+               /* Too short, this can't be a valid frame. */
+               dev_kfree_skb_any(skb);
+               return NETDEV_TX_OK;
+       }
+       B43_WARN_ON(skb_shinfo(skb)->nr_frags);
+
+       skb_queue_tail(&wl->tx_queue, skb);
+       ieee80211_queue_work(wl->hw, &wl->tx_work);
 
-drop_packet:
-       /* We can not transmit this packet. Drop it. */
-       dev_kfree_skb_any(skb);
        return NETDEV_TX_OK;
 }
 
@@ -3686,18 +3688,12 @@ static int b43_op_set_key(struct ieee80211_hw *hw, enum set_key_cmd cmd,
        u8 algorithm;
        u8 index;
        int err;
-       unsigned long flags;
        static const u8 bcast_addr[ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
 
        if (modparam_nohwcrypt)
                return -ENOSPC; /* User disabled HW-crypto */
 
        mutex_lock(&wl->mutex);
-       write_lock_irqsave(&wl->tx_lock, flags);
-       /* mutex     -> Every config operation must take it.
-        * tx_lock   -> We modify the dev->key array, which is accessed
-        *              in the TX handler.
-        */
 
        dev = wl->current_dev;
        err = -ENODEV;
@@ -3789,7 +3785,6 @@ out_unlock:
                       sta ? sta->addr : bcast_addr);
                b43_dump_keymemory(dev);
        }
-       write_unlock_irqrestore(&wl->tx_lock, flags);
        mutex_unlock(&wl->mutex);
 
        return err;
@@ -3846,9 +3841,10 @@ redo:
        if (!dev || b43_status(dev) < B43_STAT_STARTED)
                return dev;
 
-       /* Disable periodic work. Unlock to avoid deadlocks. */
+       /* Cancel work. Unlock to avoid deadlocks. */
        mutex_unlock(&wl->mutex);
        cancel_delayed_work_sync(&dev->periodic_work);
+       cancel_work_sync(&wl->tx_work);
        mutex_lock(&wl->mutex);
        dev = wl->current_dev;
        if (!dev || b43_status(dev) < B43_STAT_STARTED) {
@@ -3883,6 +3879,10 @@ redo:
        }
        B43_WARN_ON(b43_read32(dev, B43_MMIO_GEN_IRQ_MASK));
 
+       /* Drain the TX queue */
+       while (skb_queue_len(&wl->tx_queue))
+               dev_kfree_skb(skb_dequeue(&wl->tx_queue));
+
        b43_pio_stop(dev);
        b43_mac_suspend(dev);
        free_irq(dev->dev->irq, dev);
@@ -4866,7 +4866,6 @@ static int b43_wireless_init(struct ssb_device *dev)
 
        /* Initialize struct b43_wl */
        wl->hw = hw;
-       rwlock_init(&wl->tx_lock);
        spin_lock_init(&wl->leds_lock);
        spin_lock_init(&wl->shm_lock);
        mutex_init(&wl->mutex);
@@ -4874,6 +4873,8 @@ static int b43_wireless_init(struct ssb_device *dev)
        INIT_LIST_HEAD(&wl->devlist);
        INIT_WORK(&wl->beacon_update_trigger, b43_beacon_update_trigger_work);
        INIT_WORK(&wl->txpower_adjust_work, b43_phy_txpower_adjust_work);
+       INIT_WORK(&wl->tx_work, b43_tx_work);
+       skb_queue_head_init(&wl->tx_queue);
 
        ssb_set_devtypedata(dev, wl);
        b43info(wl, "Broadcom %04X WLAN found (core revision %u)\n",