diff --git a/[refs] b/[refs]
index 06232f417cc9..9053da36c048 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: d73f30e1c9a9af14757fa5bf4014343926047156
+refs/heads/master: 4112e16a7c606a80810d22d55bfc742eaa61fecb
diff --git a/trunk/drivers/ata/libata-sff.c b/trunk/drivers/ata/libata-sff.c
index 12c88c588039..cfa9ed179d9c 100644
--- a/trunk/drivers/ata/libata-sff.c
+++ b/trunk/drivers/ata/libata-sff.c
@@ -832,6 +832,21 @@ void ata_bmdma_post_internal_cmd(struct ata_queued_cmd *qc)
 }
 
 #ifdef CONFIG_PCI
+
+static int ata_resources_present(struct pci_dev *pdev, int port)
+{
+	int i;
+	
+	/* Check the PCI resources for this channel are enabled */
+	port = port * 2;
+	for (i = 0; i < 2; i ++) {
+		if (pci_resource_start(pdev, port + i) == 0 ||
+			pci_resource_len(pdev, port + i) == 0)
+		return 0;
+	}
+	return 1;
+}
+		
 /**
  *	ata_pci_init_native_mode - Initialize native-mode driver
  *	@pdev:  pci device to be initialized
@@ -863,6 +878,13 @@ ata_pci_init_native_mode(struct pci_dev *pdev, struct ata_port_info **port, int
 
 	probe_ent->irq = pdev->irq;
 	probe_ent->irq_flags = IRQF_SHARED;
+	
+	/* Discard disabled ports. Some controllers show their
+	   unused channels this way */
+	if (ata_resources_present(pdev, 0) == 0)
+		ports &= ~ATA_PORT_PRIMARY;
+	if (ata_resources_present(pdev, 1) == 0)
+		ports &= ~ATA_PORT_SECONDARY;
 
 	if (ports & ATA_PORT_PRIMARY) {
 		probe_ent->port[p].cmd_addr = pci_resource_start(pdev, 0);