libata: don't clamp queue depth to ATA_MAX_QUEUE - 1

Use what the driver provides, which will still be ATA_MAX_QUEUE - 1
at most anyway.
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NTejun Heo <tj@kernel.org>

drivers/ata/libata-core.c

@@ -2286,7 +2286,7 @@ static int ata_dev_config_ncq(struct ata_device *dev,
 		return 0;
 	}
 	if (ap->flags & ATA_FLAG_NCQ) {
-		hdepth = min(ap->scsi_host->can_queue, ATA_MAX_QUEUE - 1);
+		hdepth = min(ap->scsi_host->can_queue, ATA_MAX_QUEUE);
 		dev->flags |= ATA_DFLAG_NCQ;
 	}
 
@@ -6408,7 +6408,7 @@ void ata_host_init(struct ata_host *host, struct device *dev,
 {
 	spin_lock_init(&host->lock);
 	mutex_init(&host->eh_mutex);
-	host->n_tags = ATA_MAX_QUEUE - 1;
+	host->n_tags = ATA_MAX_QUEUE;
 	host->dev = dev;
 	host->ops = ops;
 }
@@ -6490,7 +6490,7 @@ int ata_host_register(struct ata_host *host, struct scsi_host_template *sht)
 {
 	int i, rc;
 
-	host->n_tags = clamp(sht->can_queue, 1, ATA_MAX_QUEUE - 1);
+	host->n_tags = clamp(sht->can_queue, 1, ATA_MAX_QUEUE);
 
 	/* host must have been started */
 	if (!(host->flags & ATA_HOST_STARTED)) {

drivers/ata/libata-scsi.c

@@ -1319,7 +1319,7 @@ static int ata_scsi_dev_config(struct scsi_device *sdev,
 		int depth;
 
 		depth = min(sdev->host->can_queue, ata_id_queue_depth(dev->id));
-		depth = min(ATA_MAX_QUEUE - 1, depth);
+		depth = min(ATA_MAX_QUEUE, depth);
 		scsi_change_queue_depth(sdev, depth);
 	}
 
@@ -1432,7 +1432,7 @@ int __ata_change_queue_depth(struct ata_port *ap, struct scsi_device *sdev,
 	/* limit and apply queue depth */
 	queue_depth = min(queue_depth, sdev->host->can_queue);
 	queue_depth = min(queue_depth, ata_id_queue_depth(dev->id));
-	queue_depth = min(queue_depth, ATA_MAX_QUEUE - 1);
+	queue_depth = min(queue_depth, ATA_MAX_QUEUE);
 
 	if (sdev->queue_depth == queue_depth)
 		return -EINVAL;