libata: kill ATA_HORKAGE_DMA_RW_ONLY

ATA_HORKAGE_DMA_RW_ONLY for TORiSAN is verified to be subset of using
DMA for ATAPI commands which aren't aligned to 16 bytes.  As libata
now doesn't use DMA for unaligned ATAPI commands, the horkage is
redundant.  Kill it.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

drivers/ata/libata-core.c

@@ -2046,10 +2046,6 @@ int ata_dev_configure(struct ata_device *dev)
 		dev->max_sectors = min_t(unsigned int, ATA_MAX_SECTORS_128,
 					 dev->max_sectors);
 
-	/* limit ATAPI DMA to R/W commands only */
-	if (ata_device_blacklisted(dev) & ATA_HORKAGE_DMA_RW_ONLY)
-		dev->horkage |= ATA_HORKAGE_DMA_RW_ONLY;
-
 	if (ap->ops->dev_config)
 		ap->ops->dev_config(dev);
 
@@ -3780,8 +3776,7 @@ static const struct ata_blacklist_entry ata_device_blacklist [] = {
 	{ "IOMEGA  ZIP 250       ATAPI", NULL,	ATA_HORKAGE_NODMA }, /* temporary fix */
 
 	/* Weird ATAPI devices */
-	{ "TORiSAN DVD-ROM DRD-N216", NULL,	ATA_HORKAGE_MAX_SEC_128 |
-						ATA_HORKAGE_DMA_RW_ONLY },
+	{ "TORiSAN DVD-ROM DRD-N216", NULL,	ATA_HORKAGE_MAX_SEC_128 },
 
 	/* Devices we expect to fail diagnostics */
 

include/linux/libata.h

@@ -298,7 +298,6 @@ enum {
 	ATA_HORKAGE_NODMA	= (1 << 1),	/* DMA problems */
 	ATA_HORKAGE_NONCQ	= (1 << 2),	/* Don't use NCQ */
 	ATA_HORKAGE_MAX_SEC_128	= (1 << 3),	/* Limit max sects to 128 */
-	ATA_HORKAGE_DMA_RW_ONLY	= (1 << 4),	/* ATAPI DMA for RW only */
 };
 
 enum hsm_task_states {