[PATCH] libata: minor patch for ATA_DFLAG_PIO

Problem:
 - With 2.6.17 libata, some PIO-only devices are given DMA commands.

Changes:
 - Do not clear the ATA_DFLAG_PIO flag in ata_dev_configure().
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Albert Lee <albertcc@tw.ibm.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>

drivers/scsi/libata-core.c

@@ -1229,7 +1229,7 @@ static int ata_dev_configure(struct ata_port *ap, struct ata_device *dev,
 		       id[84], id[85], id[86], id[87], id[88]);
 
 	/* initialize to-be-configured parameters */
-	dev->flags = 0;
+	dev->flags &= ~ATA_DFLAG_CFG_MASK;
 	dev->max_sectors = 0;
 	dev->cdb_len = 0;
 	dev->n_sectors = 0;

include/linux/libata.h

@@ -120,9 +120,12 @@ enum {
 	ATA_SHT_USE_CLUSTERING	= 1,
 
 	/* struct ata_device stuff */
-	ATA_DFLAG_LBA48		= (1 << 0), /* device supports LBA48 */
-	ATA_DFLAG_PIO		= (1 << 1), /* device currently in PIO mode */
-	ATA_DFLAG_LBA		= (1 << 2), /* device supports LBA */
+	ATA_DFLAG_LBA		= (1 << 0), /* device supports LBA */
+	ATA_DFLAG_LBA48		= (1 << 1), /* device supports LBA48 */
+
+	ATA_DFLAG_CFG_MASK	= (1 << 8) - 1,
+
+	ATA_DFLAG_PIO		= (1 << 8), /* device currently in PIO mode */
 
 	ATA_DEV_UNKNOWN		= 0,	/* unknown device */
 	ATA_DEV_ATA		= 1,	/* ATA device */