[SCSI] qla4xxx: Fix failure of mbox 0x31

Issue:
While unloading driver MBOX 0x31 fail as DDB logout (MBOX 0x56)
operation is not completed.

Fix:
Wait for DDB Logout completion before MBOX 0x31

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_os.c

@@ -8886,10 +8886,56 @@ static void qla4xxx_prevent_other_port_reinit(struct scsi_qla_host *ha)
 	}
 }
 
+static void qla4xxx_destroy_ddb(struct scsi_qla_host *ha,
+		struct ddb_entry *ddb_entry)
+{
+	struct dev_db_entry *fw_ddb_entry = NULL;
+	dma_addr_t fw_ddb_entry_dma;
+	unsigned long wtime;
+	uint32_t ddb_state;
+	int options;
+	int status;
+
+	options = LOGOUT_OPTION_CLOSE_SESSION;
+	if (qla4xxx_session_logout_ddb(ha, ddb_entry, options) == QLA_ERROR) {
+		ql4_printk(KERN_ERR, ha, "%s: Logout failed\n", __func__);
+		goto clear_ddb;
+	}
+
+	fw_ddb_entry = dma_alloc_coherent(&ha->pdev->dev, sizeof(*fw_ddb_entry),
+					  &fw_ddb_entry_dma, GFP_KERNEL);
+	if (!fw_ddb_entry) {
+		ql4_printk(KERN_ERR, ha,
+			   "%s: Unable to allocate dma buffer\n", __func__);
+		goto clear_ddb;
+	}
+
+	wtime = jiffies + (HZ * LOGOUT_TOV);
+	do {
+		status = qla4xxx_get_fwddb_entry(ha, ddb_entry->fw_ddb_index,
+						 fw_ddb_entry, fw_ddb_entry_dma,
+						 NULL, NULL, &ddb_state, NULL,
+						 NULL, NULL);
+		if (status == QLA_ERROR)
+			goto free_ddb;
+
+		if ((ddb_state == DDB_DS_NO_CONNECTION_ACTIVE) ||
+		    (ddb_state == DDB_DS_SESSION_FAILED))
+			goto free_ddb;
+
+		schedule_timeout_uninterruptible(HZ);
+	} while ((time_after(wtime, jiffies)));
+
+free_ddb:
+	dma_free_coherent(&ha->pdev->dev, sizeof(*fw_ddb_entry),
+			  fw_ddb_entry, fw_ddb_entry_dma);
+clear_ddb:
+	qla4xxx_clear_ddb_entry(ha, ddb_entry->fw_ddb_index);
+}
+
 static void qla4xxx_destroy_fw_ddb_session(struct scsi_qla_host *ha)
 {
 	struct ddb_entry *ddb_entry;
-	int options;
 	int idx;
 
 	for (idx = 0; idx < MAX_DDB_ENTRIES; idx++) {
@@ -8898,13 +8944,7 @@ static void qla4xxx_destroy_fw_ddb_session(struct scsi_qla_host *ha)
 		if ((ddb_entry != NULL) &&
 		    (ddb_entry->ddb_type == FLASH_DDB)) {
 
-			options = LOGOUT_OPTION_CLOSE_SESSION;
-			if (qla4xxx_session_logout_ddb(ha, ddb_entry, options)
-			    == QLA_ERROR)
-				ql4_printk(KERN_ERR, ha, "%s: Logout failed\n",
-					   __func__);
-
-			qla4xxx_clear_ddb_entry(ha, ddb_entry->fw_ddb_index);
+			qla4xxx_destroy_ddb(ha, ddb_entry);
 			/*
 			 * we have decremented the reference count of the driver
 			 * when we setup the session to have the driver unload