diff --git a/[refs] b/[refs]
index 7e930e29ea49..8f4eccc1f581 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 41bbc8bf1ab0e3e7cda1a0334176a9aa3986cd30
+refs/heads/master: d33d44facc8673388979297c9836b4bf590f7388
diff --git a/trunk/drivers/scsi/libata-bmdma.c b/trunk/drivers/scsi/libata-bmdma.c
index a89e44b21f4d..999725ca8d09 100644
--- a/trunk/drivers/scsi/libata-bmdma.c
+++ b/trunk/drivers/scsi/libata-bmdma.c
@@ -700,5 +700,41 @@ int ata_pci_init_one (struct pci_dev *pdev, struct ata_port_info **port_info,
 	return rc;
 }
 
+/**
+ *	ata_pci_clear_simplex	-	attempt to kick device out of simplex
+ *	@pdev: PCI device
+ *
+ *	Some PCI ATA devices report simplex mode but in fact can be told to
+ *	enter non simplex mode. This implements the neccessary logic to 
+ *	perform the task on such devices. Calling it on other devices will
+ *	have -undefined- behaviour.
+ */
+
+int ata_pci_clear_simplex(struct pci_dev *pdev)
+{
+	unsigned long bmdma = pci_resource_start(pdev, 4);
+	u8 simplex;
+
+	if (bmdma == 0)
+		return -ENOENT;
+
+	simplex = inb(bmdma + 0x02);
+	outb(simplex & 0x60, bmdma + 0x02);
+	simplex = inb(bmdma + 0x02);
+	if (simplex & 0x80)
+		return -EOPNOTSUPP;
+	return 0;
+}
+
+unsigned long ata_pci_default_filter(const struct ata_port *ap, struct ata_device *adev, unsigned long xfer_mask)
+{
+	/* Filter out DMA modes if the device has been configured by
+	   the BIOS as PIO only */
+	   
+	if (ap->ioaddr.bmdma_addr == 0)
+		xfer_mask &= ~(ATA_MASK_MWDMA | ATA_MASK_UDMA);
+	return xfer_mask;
+}
+
 #endif /* CONFIG_PCI */