From: Grant Grundler <[EMAIL PROTECTED]>

IRQs are racing with tulip_down(). DMA can be restarted by the
interrupt handler _after_ we call tulip_stop_rxtx() and the DMA
buffers are unmapped.  The result is an MCA (hard crash on ia64)
because of an IO TLB miss.  The long-term fix is to make the interrupt
handler shutdown aware.

Signed-off-by: Grant Grundler <[EMAIL PROTECTED]>
Acked-by: Valerie Henson <[EMAIL PROTECTED]>

---

 tulip_core.c |   37 ++++++++++++++++++++++++-------------
 1 files changed, 24 insertions(+), 13 deletions(-)

diff -Nru a/drivers/net/tulip/tulip_core.c b/drivers/net/tulip/tulip_core.c
--- a/drivers/net/tulip/tulip_core.c    2006-06-22 16:24:11 -07:00
+++ b/drivers/net/tulip/tulip_core.c    2006-06-22 16:24:11 -07:00
@@ -18,11 +18,11 @@
 
 #define DRV_NAME       "tulip"
 #ifdef CONFIG_TULIP_NAPI
-#define DRV_VERSION    "1.1.13-NAPI" /* Keep at least for test */
+#define DRV_VERSION    "1.1.14-NAPI" /* Keep at least for test */
 #else
-#define DRV_VERSION    "1.1.13"
+#define DRV_VERSION    "1.1.14"
 #endif
-#define DRV_RELDATE    "May 11, 2002"
+#define DRV_RELDATE    "May 6, 2006"
 
 
 #include <linux/module.h>
@@ -739,23 +739,36 @@
 #endif
        spin_lock_irqsave (&tp->lock, flags);
 
+       /*
+         FIXME: We should really add a shutdown-in-progress flag and
+         check it in the interrupt handler to see whether we should
+         reenable DMA or not.  The preferred ordering here would be:
+        
+         stop DMA engine
+         disable interrupts
+         remove DMA resources
+         free_irq()
+
+         The below works but is non-obvious and doesn't match the
+         ordering of bring-up. -VAL
+       */
+
        /* Disable interrupts by clearing the interrupt mask. */
        iowrite32 (0x00000000, ioaddr + CSR7);
+       ioread32 (ioaddr + CSR7);       /* flush posted write */
 
-       /* Stop the Tx and Rx processes. */
-       tulip_stop_rxtx(tp);
+       spin_unlock_irqrestore (&tp->lock, flags);
 
-       /* prepare receive buffers */
-       tulip_refill_rx(dev);
+       free_irq (dev->irq, dev);       /* no more races after this */
+       tulip_stop_rxtx(tp);            /* Stop DMA */
 
-       /* release any unconsumed transmit buffers */
-       tulip_clean_tx_ring(tp);
+       /* Put driver back into the state we start with */
+       tulip_refill_rx(dev);           /* prepare RX buffers */
+       tulip_clean_tx_ring(tp);        /* clean up unsent TX buffers */
 
        if (ioread32 (ioaddr + CSR6) != 0xffffffff)
                tp->stats.rx_missed_errors += ioread32 (ioaddr + CSR8) & 0xffff;
 
-       spin_unlock_irqrestore (&tp->lock, flags);
-
        init_timer(&tp->timer);
        tp->timer.data = (unsigned long)dev;
        tp->timer.function = tulip_tbl[tp->chip_id].media_timer;
@@ -781,7 +794,6 @@
                printk (KERN_DEBUG "%s: Shutting down ethercard, status was 
%2.2x.\n",
                        dev->name, ioread32 (ioaddr + CSR5));
 
-       free_irq (dev->irq, dev);
 
        /* Free all the skbuffs in the Rx queue. */
        for (i = 0; i < RX_RING_SIZE; i++) {
@@ -1752,7 +1764,6 @@
                tulip_down(dev);
 
        netif_device_detach(dev);
-       free_irq(dev->irq, dev);
 
        pci_save_state(pdev);
        pci_disable_device(pdev);
-
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