1 files changed, 55 insertions, 19 deletions

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index c02c490122d..f888babc828 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -826,30 +826,61 @@ static void ata_scsi_sdev_config(struct scsi_device *sdev)
 	sdev->max_device_blocked = 1;
 }
 
-static void ata_scsi_dev_config(struct scsi_device *sdev,
-				struct ata_device *dev)
+/**
+ *	atapi_drain_needed - Check whether data transfer may overflow
+ *	@rq: request to be checked
+ *
+ *	ATAPI commands which transfer variable length data to host
+ *	might overflow due to application error or hardare bug.  This
+ *	function checks whether overflow should be drained and ignored
+ *	for @request.
+ *
+ *	LOCKING:
+ *	None.
+ *
+ *	RETURNS:
+ *	1 if ; otherwise, 0.
+ */
+static int atapi_drain_needed(struct request *rq)
+{
+	if (likely(!blk_pc_request(rq)))
+		return 0;
+
+	if (!rq->data_len || (rq->cmd_flags & REQ_RW))
+		return 0;
+
+	return atapi_cmd_type(rq->cmd[0]) == ATAPI_MISC;
+}
+
+static int ata_scsi_dev_config(struct scsi_device *sdev,
+			       struct ata_device *dev)
 {
 	/* configure max sectors */
 	blk_queue_max_sectors(sdev->request_queue, dev->max_sectors);
 
-	/* SATA DMA transfers must be multiples of 4 byte, so
-	 * we need to pad ATAPI transfers using an extra sg.
-	 * Decrement max hw segments accordingly.
-	 */
 	if (dev->class == ATA_DEV_ATAPI) {
 		struct request_queue *q = sdev->request_queue;
-		blk_queue_max_hw_segments(q, q->max_hw_segments - 1);
+		void *buf;
 
 		/* set the min alignment */
 		blk_queue_update_dma_alignment(sdev->request_queue,
 					       ATA_DMA_PAD_SZ - 1);
-	} else
+
+		/* configure draining */
+		buf = kmalloc(ATAPI_MAX_DRAIN, q->bounce_gfp | GFP_KERNEL);
+		if (!buf) {
+			ata_dev_printk(dev, KERN_ERR,
+				       "drain buffer allocation failed\n");
+			return -ENOMEM;
+		}
+
+		blk_queue_dma_drain(q, atapi_drain_needed, buf, ATAPI_MAX_DRAIN);
+	} else {
 		/* ATA devices must be sector aligned */
 		blk_queue_update_dma_alignment(sdev->request_queue,
 					       ATA_SECT_SIZE - 1);
-
-	if (dev->class == ATA_DEV_ATA)
 		sdev->manage_start_stop = 1;
+	}
 
 	if (dev->flags & ATA_DFLAG_AN)
 		set_bit(SDEV_EVT_MEDIA_CHANGE, sdev->supported_events);
@@ -861,6 +892,8 @@ static void ata_scsi_dev_config(struct scsi_device *sdev,
 		depth = min(ATA_MAX_QUEUE - 1, depth);
 		scsi_adjust_queue_depth(sdev, MSG_SIMPLE_TAG, depth);
 	}
+
+	return 0;
 }
 
 /**
@@ -879,13 +912,14 @@ int ata_scsi_slave_config(struct scsi_device *sdev)
 {
 	struct ata_port *ap = ata_shost_to_port(sdev->host);
 	struct ata_device *dev = __ata_scsi_find_dev(ap, sdev);
+	int rc = 0;
 
 	ata_scsi_sdev_config(sdev);
 
 	if (dev)
-		ata_scsi_dev_config(sdev, dev);
+		rc = ata_scsi_dev_config(sdev, dev);
 
-	return 0;
+	return rc;
 }
 
 /**
@@ -905,6 +939,7 @@ int ata_scsi_slave_config(struct scsi_device *sdev)
 void ata_scsi_slave_destroy(struct scsi_device *sdev)
 {
 	struct ata_port *ap = ata_shost_to_port(sdev->host);
+	struct request_queue *q = sdev->request_queue;
 	unsigned long flags;
 	struct ata_device *dev;
 
@@ -920,6 +955,10 @@ void ata_scsi_slave_destroy(struct scsi_device *sdev)
 		ata_port_schedule_eh(ap);
 	}
 	spin_unlock_irqrestore(ap->lock, flags);
+
+	kfree(q->dma_drain_buffer);
+	q->dma_drain_buffer = NULL;
+	q->dma_drain_size = 0;
 }
 
 /**
@@ -1862,7 +1901,7 @@ unsigned int ata_scsiop_inq_83(struct ata_scsi_args *args, u8 *rbuf,
  *	spin_lock_irqsave(host lock)
  */
 
-unsigned int ata_scsiop_inq_89(struct ata_scsi_args *args, u8 *rbuf,
+static unsigned int ata_scsiop_inq_89(struct ata_scsi_args *args, u8 *rbuf,
 			      unsigned int buflen)
 {
 	u8 pbuf[60];
@@ -2500,7 +2539,7 @@ static unsigned int atapi_xlat(struct ata_queued_cmd *qc)
 	 * want to set it properly, and for DMA where it is
 	 * effectively meaningless.
 	 */
-	nbytes = min(qc->nbytes, (unsigned int)63 * 1024);
+	nbytes = min(scmd->request->raw_data_len, (unsigned int)63 * 1024);
 
 	/* Most ATAPI devices which honor transfer chunk size don't
 	 * behave according to the spec when odd chunk size which
@@ -3555,7 +3594,7 @@ EXPORT_SYMBOL_GPL(ata_sas_port_alloc);
  *	@ap: Port to initialize
  *
  *	Called just after data structures for each port are
- *	initialized.  Allocates DMA pad.
+ *	initialized.
  *
  *	May be used as the port_start() entry in ata_port_operations.
  *
@@ -3564,7 +3603,7 @@ EXPORT_SYMBOL_GPL(ata_sas_port_alloc);
  */
 int ata_sas_port_start(struct ata_port *ap)
 {
-	return ata_pad_alloc(ap, ap->dev);
+	return 0;
 }
 EXPORT_SYMBOL_GPL(ata_sas_port_start);
 
@@ -3572,8 +3611,6 @@ EXPORT_SYMBOL_GPL(ata_sas_port_start);
  *	ata_port_stop - Undo ata_sas_port_start()
  *	@ap: Port to shut down
  *
- *	Frees the DMA pad.
- *
  *	May be used as the port_stop() entry in ata_port_operations.
  *
  *	LOCKING:
@@ -3582,7 +3619,6 @@ EXPORT_SYMBOL_GPL(ata_sas_port_start);
 
 void ata_sas_port_stop(struct ata_port *ap)
 {
-	ata_pad_free(ap, ap->dev);
 }
 EXPORT_SYMBOL_GPL(ata_sas_port_stop);