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Diffstat (limited to 'drivers/ata/ahci.c')
-rw-r--r--drivers/ata/ahci.c18
1 files changed, 18 insertions, 0 deletions
diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 588ab2fd59e7..cb7853b7335d 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -193,6 +193,8 @@ enum {
ATA_FLAG_ACPI_SATA | ATA_FLAG_AN |
ATA_FLAG_IPM,
AHCI_LFLAG_COMMON = ATA_LFLAG_SKIP_D2H_BSY,
+
+ ICH_MAP = 0x90, /* ICH MAP register */
};
struct ahci_cmd_hdr {
@@ -2273,6 +2275,22 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
if (rc)
return rc;
+ if (pdev->vendor == PCI_VENDOR_ID_INTEL &&
+ (pdev->device == 0x2652 || pdev->device == 0x2653)) {
+ u8 map;
+
+ /* ICH6s share the same PCI ID for both piix and ahci
+ * modes. Enabling ahci mode while MAP indicates
+ * combined mode is a bad idea. Yield to ata_piix.
+ */
+ pci_read_config_byte(pdev, ICH_MAP, &map);
+ if (map & 0x3) {
+ dev_printk(KERN_INFO, &pdev->dev, "controller is in "
+ "combined mode, can't enable AHCI mode\n");
+ return -ENODEV;
+ }
+ }
+
hpriv = devm_kzalloc(dev, sizeof(*hpriv), GFP_KERNEL);
if (!hpriv)
return -ENOMEM;
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