cleanup switch in scsi_adjust_queue_depth()

While checking what scsi_adjust_queue_depth() did I thought its switch statement could be clearer.

ChangeLog:
- remove redundant assignment (to sdev->queue_depth)
- re-order cases (thus removing the fall-through)

@@ -850,6 +850,10 @@ void scsi_adjust_queue_depth(struct scsi
 
 	sdev->queue_depth = tags;
 	switch (tagged) {
+		case 0:
+			sdev->ordered_tags = 0;
+			sdev->simple_tags = 0;
+			break;
 		case MSG_ORDERED_TAG:
 			sdev->ordered_tags = 1;
 			sdev->simple_tags = 1;

@@ -859,13 +863,11 @@ void scsi_adjust_queue_depth(struct scsi
 			sdev->simple_tags = 1;
 			break;
 		default:
+			sdev->ordered_tags = 0;
+			sdev->simple_tags = 0;
 			sdev_printk(KERN_WARNING, sdev,
 				    "scsi_adjust_queue_depth, bad queue type, "
 				    "disabled\n");
-		case 0:
-			sdev->ordered_tags = sdev->simple_tags = 0;
-			sdev->queue_depth = tags;
-			break;
 	}
  out:
 	spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);

Doug> While checking what scsi_adjust_queue_depth() did I thought its Doug> switch statement could be clearer.

Doug> ChangeLog:
Doug> - remove redundant assignment (to sdev->queue_depth)
Doug> - re-order cases (thus removing the fall-through)

Doug> Signed-off-by: Douglas Gilbert <[email protected]>

I agree that the original version is a bit misleading.

Martin K. Petersen	Oracle Linux Engineering

I've run tests with tagged set to both 0 and MSG_SIMPLE_TAG and they both work like before, so you may add:

I did notice that include/scsi/scsi_tcq.h scsi_set_tag_type() is another function with a switch statement with fallthroughs setting these variables. It doesn't have default: before 0:
or involve a print, so reordering is not as necessary.

However, that function doesn't clear ordered_tags in the MSG_SIMPLE_TAG case, which seems problematic if the device is ever changed from ordered to simple. You might want to address that in this patch too.

---
Rob Elliott HP Server Storage