[BNX2]: Fix bug in irq handler and add prefetch

Fix bug in bnx2_interrupt() that caused an unnecessary register read.
The BNX2_PCICFG_MISC_STATUS should only be read when the status tag
has not changed.

Add prefetch of the status block in bnx2_msi() similar to tg3_msi().
The status block is not touched in bnx2_msi() and prefetching it will
speed up bnx2_poll() that will run on the same CPU that received the
MSI.

Update version.
Signed-off-by: NMichael Chan <mchan@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/bnx2.c

@@ -14,8 +14,8 @@
 
 #define DRV_MODULE_NAME		"bnx2"
 #define PFX DRV_MODULE_NAME	": "
-#define DRV_MODULE_VERSION	"1.2.20"
-#define DRV_MODULE_RELDATE	"August 22, 2005"
+#define DRV_MODULE_VERSION	"1.2.21"
+#define DRV_MODULE_RELDATE	"September 7, 2005"
 
 #define RUN_AT(x) (jiffies + (x))
 
@@ -1533,6 +1533,7 @@ bnx2_msi(int irq, void *dev_instance, struct pt_regs *regs)
 	struct net_device *dev = dev_instance;
 	struct bnx2 *bp = dev->priv;
 
+	prefetch(bp->status_blk);
 	REG_WR(bp, BNX2_PCICFG_INT_ACK_CMD,
 		BNX2_PCICFG_INT_ACK_CMD_USE_INT_HC_PARAM |
 		BNX2_PCICFG_INT_ACK_CMD_MASK_INT);
@@ -1558,7 +1559,7 @@ bnx2_interrupt(int irq, void *dev_instance, struct pt_regs *regs)
 	 * When using MSI, the MSI message will always complete after
 	 * the status block write.
 	 */
-	if ((bp->status_blk->status_idx == bp->last_status_idx) ||
+	if ((bp->status_blk->status_idx == bp->last_status_idx) &&
 	    (REG_RD(bp, BNX2_PCICFG_MISC_STATUS) &
 	     BNX2_PCICFG_MISC_STATUS_INTA_VALUE))
 		return IRQ_NONE;

drivers/net/bnx2.h

@@ -50,6 +50,7 @@
 #endif
 #include <linux/workqueue.h>
 #include <linux/crc32.h>
+#include <linux/prefetch.h>
 
 /* Hardware data structures and register definitions automatically
  * generated from RTL code. Do not modify.