[SCSI] qla4xxx: Don't process mbx interrupt unconditionally

Do not process interrupt unconditionally during mailbox processing  which can
lead to spurious interrupt. Mailbox completion are now polled if interrupt are
disabled or wait for interrupt to come in if its enabled

Signed-off-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <jbottomley@parallels.com>

drivers/scsi/qla4xxx/ql4_mbx.c

@@ -86,22 +86,8 @@ int qla4xxx_mailbox_command(struct scsi_qla_host *ha, uint8_t inCount,
 		msleep(10);
 	}
 
-	/* To prevent overwriting mailbox registers for a command that has
-	 * not yet been serviced, check to see if an active command
-	 * (AEN, IOCB, etc.) is interrupting, then service it.
-	 * -----------------------------------------------------------------
-	 */
 	spin_lock_irqsave(&ha->hardware_lock, flags);
 
-	if (!is_qla8022(ha)) {
-		intr_status = readl(&ha->reg->ctrl_status);
-		if (intr_status & CSR_SCSI_PROCESSOR_INTR) {
-			/* Service existing interrupt */
-			ha->isp_ops->interrupt_service_routine(ha, intr_status);
-			clear_bit(AF_MBOX_COMMAND_DONE, &ha->flags);
-		}
-	}
-
 	ha->mbox_status_count = outCount;
 	for (i = 0; i < outCount; i++)
 		ha->mbox_status[i] = 0;