1 files changed, 16 insertions, 2 deletions

diff --git a/drivers/scsi/ahci.c b/drivers/scsi/ahci.c
index 7b0640bc0079..4e96ec5f2ff9 100644
--- a/drivers/scsi/ahci.c
+++ b/drivers/scsi/ahci.c
@@ -134,6 +134,7 @@ enum {
                                   PORT_IRQ_D2H_REG_FIS,
 
         /* PORT_CMD bits */
+        PORT_CMD_ATAPI          = (1 << 24), /* Device is ATAPI */
         PORT_CMD_LIST_ON        = (1 << 15), /* cmd list DMA engine running */
         PORT_CMD_FIS_ON         = (1 << 14), /* FIS DMA engine running */
         PORT_CMD_FIS_RX         = (1 << 4), /* Enable FIS receive DMA engine */
@@ -441,7 +442,7 @@ static void ahci_phy_reset(struct ata_port *ap)
         void __iomem *port_mmio = (void __iomem *) ap->ioaddr.cmd_addr;
         struct ata_taskfile tf;
         struct ata_device *dev = &ap->device[0];
-        u32 tmp;
+        u32 new_tmp, tmp;
 
         __sata_phy_reset(ap);
 
@@ -455,8 +456,21 @@ static void ahci_phy_reset(struct ata_port *ap)
         tf.nsect        = (tmp)         & 0xff;
 
         dev->class = ata_dev_classify(&tf);
-        if (!ata_dev_present(dev))
+        if (!ata_dev_present(dev)) {
                 ata_port_disable(ap);
+                return;
+        }
+
+        /* Make sure port's ATAPI bit is set appropriately */
+        new_tmp = tmp = readl(port_mmio + PORT_CMD);
+        if (dev->class == ATA_DEV_ATAPI)
+                new_tmp |= PORT_CMD_ATAPI;
+        else
+                new_tmp &= ~PORT_CMD_ATAPI;
+        if (new_tmp != tmp) {
+                writel(new_tmp, port_mmio + PORT_CMD);
+                readl(port_mmio + PORT_CMD); /* flush */
+        }
 }
 
 static u8 ahci_check_status(struct ata_port *ap)