p54pci: revise tx locking

This patch continues the effort which began with:
"[PATCH] p54pci: move tx cleanup into tasklet".

Thanks to these changes, p54pci's interrupt & tx
cleanup routines can be made lock-less.

Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 4 insertions, 12 deletions

diff --git a/drivers/net/wireless/p54/p54pci.c b/drivers/net/wireless/p54/p54pci.c
index 48cae48ed6eb..bda29c00f3ef 100644
--- a/drivers/net/wireless/p54/p54pci.c
+++ b/drivers/net/wireless/p54/p54pci.c
@@ -238,7 +238,6 @@ static void p54p_check_tx_ring(struct ieee80211_hw *dev, u32 *index,
         int ring_index, struct p54p_desc *ring, u32 ring_limit,
         struct sk_buff **tx_buf)
 {
-        unsigned long flags;
         struct p54p_priv *priv = dev->priv;
         struct p54p_ring_control *ring_control = priv->ring_control;
         struct p54p_desc *desc;
@@ -249,7 +248,6 @@ static void p54p_check_tx_ring(struct ieee80211_hw *dev, u32 *index,
         (*index) = idx = le32_to_cpu(ring_control->device_idx[1]);
         idx %= ring_limit;
 
-        spin_lock_irqsave(&priv->lock, flags);
         while (i != idx) {
                 desc = &ring[i];
 
@@ -264,16 +262,12 @@ static void p54p_check_tx_ring(struct ieee80211_hw *dev, u32 *index,
                 desc->len = 0;
                 desc->flags = 0;
 
-                if (skb && FREE_AFTER_TX(skb)) {
-                        spin_unlock_irqrestore(&priv->lock, flags);
+                if (skb && FREE_AFTER_TX(skb))
                         p54_free_skb(dev, skb);
-                        spin_lock_irqsave(&priv->lock, flags);
-                }
 
                 i++;
                 i %= ring_limit;
         }
-        spin_unlock_irqrestore(&priv->lock, flags);
 }
 
 static void p54p_tasklet(unsigned long dev_id)
@@ -306,7 +300,6 @@ static irqreturn_t p54p_interrupt(int irq, void *dev_id)
         struct p54p_priv *priv = dev->priv;
         __le32 reg;
 
-        spin_lock(&priv->lock);
         reg = P54P_READ(int_ident);
         if (unlikely(reg == cpu_to_le32(0xFFFFFFFF))) {
                 goto out;
@@ -321,15 +314,14 @@ static irqreturn_t p54p_interrupt(int irq, void *dev_id)
                 complete(&priv->boot_comp);
 
 out:
-        spin_unlock(&priv->lock);
         return reg ? IRQ_HANDLED : IRQ_NONE;
 }
 
 static void p54p_tx(struct ieee80211_hw *dev, struct sk_buff *skb)
 {
+        unsigned long flags;
         struct p54p_priv *priv = dev->priv;
         struct p54p_ring_control *ring_control = priv->ring_control;
-        unsigned long flags;
         struct p54p_desc *desc;
         dma_addr_t mapping;
         u32 device_idx, idx, i;
@@ -370,14 +362,14 @@ static void p54p_stop(struct ieee80211_hw *dev)
         unsigned int i;
         struct p54p_desc *desc;
 
-        tasklet_kill(&priv->tasklet);
-
         P54P_WRITE(int_enable, cpu_to_le32(0));
         P54P_READ(int_enable);
         udelay(10);
 
         free_irq(priv->pdev->irq, dev);
 
+        tasklet_kill(&priv->tasklet);
+
         P54P_WRITE(dev_int, cpu_to_le32(ISL38XX_DEV_INT_RESET));
 
         for (i = 0; i < ARRAY_SIZE(priv->rx_buf_data); i++) {