b43: Fix some TX/RX locking issues

This fixes some TX/RX related locking issues.
With this patch applied, some of the PHY transmission errors are fixed.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
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 eff2a15..37783cd 100644 (file)
--- a/drivers/net/wireless/b43/b43.h
+++ b/drivers/net/wireless/b43/b43.h
@@ -691,6 +691,10 @@ struct b43_wl {
 
        struct mutex mutex;
        spinlock_t irq_lock;
+       /* R/W lock for data transmission.
+        * Transmissions on 2+ queues can run concurrently, but somebody else
+        * might sync with TX by write_lock_irqsave()'ing. */
+       rwlock_t tx_lock;
        /* Lock for LEDs access. */
        spinlock_t leds_lock;
        /* Lock for SHM access. */

diff --git a/drivers/net/wireless/b43/main.c b/drivers/net/wireless/b43/main.c
index 6c7db9a..8fdba94 100644 (file)
--- a/drivers/net/wireless/b43/main.c
+++ b/drivers/net/wireless/b43/main.c
@@ -729,6 +729,7 @@ static void b43_synchronize_irq(struct b43_wldev *dev)
  */
 void b43_dummy_transmission(struct b43_wldev *dev)
 {
+       struct b43_wl *wl = dev->wl;
        struct b43_phy *phy = &dev->phy;
        unsigned int i, max_loop;
        u16 value;
@@ -755,6 +756,9 @@ void b43_dummy_transmission(struct b43_wldev *dev)
                return;
        }
 
+       spin_lock_irq(&wl->irq_lock);
+       write_lock(&wl->tx_lock);
+
        for (i = 0; i < 5; i++)
                b43_ram_write(dev, i * 4, buffer[i]);
 
@@ -795,6 +799,9 @@ void b43_dummy_transmission(struct b43_wldev *dev)
        }
        if (phy->radio_ver == 0x2050 && phy->radio_rev <= 0x5)
                b43_radio_write16(dev, 0x0051, 0x0037);
+
+       write_unlock(&wl->tx_lock);
+       spin_unlock_irq(&wl->irq_lock);
 }
 
 static void key_write(struct b43_wldev *dev,
@@ -2840,24 +2847,31 @@ static int b43_op_tx(struct ieee80211_hw *hw,
 {
        struct b43_wl *wl = hw_to_b43_wl(hw);
        struct b43_wldev *dev = wl->current_dev;
-       int err = -ENODEV;
+       unsigned long flags;
+       int err;
 
        if (unlikely(skb->len < 2 + 2 + 6)) {
                /* Too short, this can't be a valid frame. */
-               return -EINVAL;
+               dev_kfree_skb_any(skb);
+               return NETDEV_TX_OK;
        }
        B43_WARN_ON(skb_shinfo(skb)->nr_frags);
-
        if (unlikely(!dev))
-               goto out;
-       if (unlikely(b43_status(dev) < B43_STAT_STARTED))
-               goto out;
-       /* TX is done without a global lock. */
-       if (b43_using_pio_transfers(dev))
-               err = b43_pio_tx(dev, skb, ctl);
-       else
-               err = b43_dma_tx(dev, skb, ctl);
-out:
+               return NETDEV_TX_BUSY;
+
+       /* Transmissions on seperate queues can run concurrently. */
+       read_lock_irqsave(&wl->tx_lock, flags);
+
+       err = -ENODEV;
+       if (likely(b43_status(dev) >= B43_STAT_STARTED)) {
+               if (b43_using_pio_transfers(dev))
+                       err = b43_pio_tx(dev, skb, ctl);
+               else
+                       err = b43_dma_tx(dev, skb, ctl);
+       }
+
+       read_unlock_irqrestore(&wl->tx_lock, flags);
+
        if (unlikely(err))
                return NETDEV_TX_BUSY;
        return NETDEV_TX_OK;
@@ -3476,7 +3490,9 @@ static void b43_wireless_core_stop(struct b43_wldev *dev)
        spin_unlock_irqrestore(&wl->irq_lock, flags);
        b43_synchronize_irq(dev);
 
+       write_lock_irqsave(&wl->tx_lock, flags);
        b43_set_status(dev, B43_STAT_INITIALIZED);
+       write_unlock_irqrestore(&wl->tx_lock, flags);
 
        b43_pio_stop(dev);
        mutex_unlock(&wl->mutex);
@@ -3485,8 +3501,6 @@ static void b43_wireless_core_stop(struct b43_wldev *dev)
        cancel_delayed_work_sync(&dev->periodic_work);
        mutex_lock(&wl->mutex);
 
-       ieee80211_stop_queues(wl->hw);  //FIXME this could cause a deadlock, as mac80211 seems buggy.
-
        b43_mac_suspend(dev);
        free_irq(dev->dev->irq, dev);
        b43dbg(wl, "Wireless interface stopped\n");
@@ -4498,6 +4512,7 @@ static int b43_wireless_init(struct ssb_device *dev)
        memset(wl, 0, sizeof(*wl));
        wl->hw = hw;
        spin_lock_init(&wl->irq_lock);
+       rwlock_init(&wl->tx_lock);
        spin_lock_init(&wl->leds_lock);
        spin_lock_init(&wl->shm_lock);
        mutex_init(&wl->mutex);