libata: Limit ATAPI DMA to R/W commands only for TORiSAN DVD drives (take 3)

patch 4/4:

  Limit ATAPI DMA to R/W commands only for TORiSAN DRD-N216 DVD-ROM drives
  (http://bugzilla.kernel.org/show_bug.cgi?id=6710)

Signed-off-by: Albert Lee <albertcc@tw.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

2 files changed, 27 insertions, 1 deletions

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 84f6f8575966..cf2338cbe4ea 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -1787,6 +1787,10 @@ int ata_dev_configure(struct ata_device *dev)
         if (ata_device_blacklisted(dev) & ATA_HORKAGE_MAX_SEC_128)
                 dev->max_sectors = min(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(ap, dev);
 
@@ -3356,7 +3360,8 @@ static const struct ata_blacklist_entry ata_device_blacklist [] = {
         { "SAMSUNG CD-ROM SN-124","N001",       ATA_HORKAGE_NODMA },
 
         /* Weird ATAPI devices */
-        { "TORiSAN DVD-ROM DRD-N216", NULL,     ATA_HORKAGE_MAX_SEC_128 },
+        { "TORiSAN DVD-ROM DRD-N216", NULL,     ATA_HORKAGE_MAX_SEC_128 |
+                                                ATA_HORKAGE_DMA_RW_ONLY },
 
         /* Devices we expect to fail diagnostics */
 
@@ -3680,6 +3685,26 @@ int ata_check_atapi_dma(struct ata_queued_cmd *qc)
         struct ata_port *ap = qc->ap;
         int rc = 0; /* Assume ATAPI DMA is OK by default */
 
+        /* some drives can only do ATAPI DMA on read/write */
+        if (unlikely(qc->dev->horkage & ATA_HORKAGE_DMA_RW_ONLY)) {
+                struct scsi_cmnd *cmd = qc->scsicmd;
+                u8 *scsicmd = cmd->cmnd;
+
+                switch (scsicmd[0]) {
+                case READ_10:
+                case WRITE_10:
+                case READ_12:
+                case WRITE_12:
+                case READ_6:
+                case WRITE_6:
+                        /* atapi dma maybe ok */
+                        break;
+                default:
+                        /* turn off atapi dma */
+                        return 1;
+                }
+        }
+
         if (ap->ops->check_atapi_dma)
                 rc = ap->ops->check_atapi_dma(qc);
 
diff --git a/include/linux/libata.h b/include/linux/libata.h
index c04aec360406..0cfbcb6f08eb 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -312,6 +312,7 @@ 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 {