[PATCH] tg3 shutdown sequence update

[Jeff Garzik <jgarzik@xxxxxxxxx>]

This patch is only for testing and comment, _not_ for applying.
(testers requested)

The attached patch updates the tg3 net driver shutdown sequence to be a 
bit more correct WRT the documented sequence.  Detailed changes:

* bail out of tg3_stop_block ASAP if block is already disabled
* use standard tg3_stop_block to disable RX MAC mode.  this adds polling 
of the the enable bit to the standard code.
* just in case, shut down DMA completion between send data completion 
shutdown and send DB completion shutdown
* use standard tg3_stop_block to disable TX MAC mode.
* don't bother to disable MAC_MODE_TDE_ENABLE bit manually, TX MAC mode 
disable does it for us.
* add PCI posting flush for flow-through queues

Does this look ok WRT errata and hardware seen in the field?

One potential concern is that the error handling if tg3_stop_block fails 
runs through all the blocks unconditionally, and then returns an error. 
 It does not bail early if some of the stop-block calls fail.

Comments?

        Jeff


--- drivers/net/tg3.c.~1~       Tue Nov 19 15:30:41 2002
+++ drivers/net/tg3.c   Tue Nov 19 15:31:34 2002
@@ -2367,6 +2367,7 @@
        unsigned int i;
        u32 len, entry, base_flags, mss;
        int would_hit_hwbug;
+       unsigned long flags;
 
        len = (skb->len - skb->data_len);
 
@@ -2389,12 +2390,12 @@
         * So we really do need to disable interrupts when taking
         * tx_lock here.
         */
-       spin_lock_irq(&tp->tx_lock);
+       spin_lock_irqsave(&tp->tx_lock, flags);
 
        /* This is a hard error, log it. */
        if (unlikely(TX_BUFFS_AVAIL(tp) <= (skb_shinfo(skb)->nr_frags + 1))) {
                netif_stop_queue(dev);
-               spin_unlock_irq(&tp->tx_lock);
+               spin_unlock_irqrestore(&tp->tx_lock, flags);
                printk(KERN_ERR PFX "%s: BUG! Tx Ring full when queue awake!\n",
                       dev->name);
                return 1;
@@ -2535,7 +2536,7 @@
                netif_stop_queue(dev);
 
 out_unlock:
-       spin_unlock_irq(&tp->tx_lock);
+       spin_unlock_irqrestore(&tp->tx_lock, flags);
 
        dev->trans_start = jiffies;
 
@@ -2547,6 +2548,7 @@
        struct tg3 *tp = dev->priv;
        dma_addr_t mapping;
        u32 len, entry, base_flags, mss;
+       unsigned long flags;
 
        len = (skb->len - skb->data_len);
 
@@ -2569,12 +2571,12 @@
         * So we really do need to disable interrupts when taking
         * tx_lock here.
         */
-       spin_lock_irq(&tp->tx_lock);
+       spin_lock_irqsave(&tp->tx_lock, flags);
 
        /* This is a hard error, log it. */
        if (unlikely(TX_BUFFS_AVAIL(tp) <= (skb_shinfo(skb)->nr_frags + 1))) {
                netif_stop_queue(dev);
-               spin_unlock_irq(&tp->tx_lock);
+               spin_unlock_irqrestore(&tp->tx_lock, flags);
                printk(KERN_ERR PFX "%s: BUG! Tx Ring full when queue awake!\n",
                       dev->name);
                return 1;
@@ -2665,7 +2667,7 @@
        if (TX_BUFFS_AVAIL(tp) <= (MAX_SKB_FRAGS + 1))
                netif_stop_queue(dev);
 
-       spin_unlock_irq(&tp->tx_lock);
+       spin_unlock_irqrestore(&tp->tx_lock, flags);
 
        dev->trans_start = jiffies;