1 files changed, 9 insertions, 10 deletions

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index aeb6e01d82ce..57a43649a461 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -1637,6 +1637,7 @@ defer:
 
 /**
  *      ata_scsi_rbuf_get - Map response buffer.
+ *      @cmd: SCSI command containing buffer to be mapped.
  *      @flags: unsigned long variable to store irq enable status
  *      @copy_in: copy in from user buffer
  *
@@ -1954,7 +1955,7 @@ static unsigned int ata_msense_ctl_mode(u8 *buf)
 
 /**
  *      ata_msense_rw_recovery - Simulate MODE SENSE r/w error recovery page
- *      @bufp: output buffer
+ *      @buf: output buffer
  *
  *      Generate a generic MODE SENSE r/w error recovery page.
  *
@@ -2342,8 +2343,8 @@ static unsigned int atapi_xlat(struct ata_queued_cmd *qc)
 {
         struct scsi_cmnd *scmd = qc->scsicmd;
         struct ata_device *dev = qc->dev;
-        int using_pio = (dev->flags & ATA_DFLAG_PIO);
         int nodata = (scmd->sc_data_direction == DMA_NONE);
+        int using_pio = !nodata && (dev->flags & ATA_DFLAG_PIO);
         unsigned int nbytes;
 
         memset(qc->cdb, 0, dev->cdb_len);
@@ -2361,7 +2362,7 @@ static unsigned int atapi_xlat(struct ata_queued_cmd *qc)
         ata_qc_set_pc_nbytes(qc);
 
         /* check whether ATAPI DMA is safe */
-        if (!using_pio && ata_check_atapi_dma(qc))
+        if (!nodata && !using_pio && atapi_check_dma(qc))
                 using_pio = 1;
 
         /* Some controller variants snoop this value for Packet
@@ -2401,13 +2402,11 @@ static unsigned int atapi_xlat(struct ata_queued_cmd *qc)
         qc->tf.lbam = (nbytes & 0xFF);
         qc->tf.lbah = (nbytes >> 8);
 
-        if (using_pio || nodata) {
-                /* no data, or PIO data xfer */
-                if (nodata)
-                        qc->tf.protocol = ATAPI_PROT_NODATA;
-                else
-                        qc->tf.protocol = ATAPI_PROT_PIO;
-        } else {
+        if (nodata)
+                qc->tf.protocol = ATAPI_PROT_NODATA;
+        else if (using_pio)
+                qc->tf.protocol = ATAPI_PROT_PIO;
+        else {
                 /* DMA data xfer */
                 qc->tf.protocol = ATAPI_PROT_DMA;
                 qc->tf.feature |= ATAPI_PKT_DMA;