SATA AHCI: Blacklist system that spins off disks during ACPI power off

Some notebooks from HP have the problem that their BIOSes attempt to
spin down hard drives before entering ACPI system states S4 and S5.
This leads to a yo-yo effect during system power-off shutdown and the
last phase of hibernation when the disk is first spun down by the
kernel and then almost immediately turned on and off by the BIOS.
This, in turn, may result in shortening the disk's life times.

To prevent this from happening we can blacklist the affected systems
using DMI information.

Blacklist HP nx6310 that uses the AHCI driver.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

drivers/ata/ahci.c

@@ -2548,6 +2548,32 @@ static void ahci_p5wdh_workaround(struct ata_host *host)
 	}
 }
 
+static bool ahci_broken_system_poweroff(struct pci_dev *pdev)
+{
+	static const struct dmi_system_id broken_systems[] = {
+		{
+			.ident = "HP Compaq nx6310",
+			.matches = {
+				DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
+				DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq nx6310"),
+			},
+			/* PCI slot number of the controller */
+			.driver_data = (void *)0x1FUL,
+		},
+
+		{ }	/* terminate list */
+	};
+	const struct dmi_system_id *dmi = dmi_first_match(broken_systems);
+
+	if (dmi) {
+		unsigned long slot = (unsigned long)dmi->driver_data;
+		/* apply the quirk only to on-board controllers */
+		return slot == PCI_SLOT(pdev->devfn);
+	}
+
+	return false;
+}
+
 static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 {
 	static int printed_version;
@@ -2647,6 +2673,12 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 		}
 	}
 
+	if (ahci_broken_system_poweroff(pdev)) {
+		pi.flags |= ATA_FLAG_NO_POWEROFF_SPINDOWN;
+		dev_info(&pdev->dev,
+			"quirky BIOS, skipping spindown on poweroff\n");
+	}
+
 	/* CAP.NP sometimes indicate the index of the last enabled
 	 * port, at other times, that of the last possible port, so
 	 * determining the maximum port number requires looking at