ata_piix: save, use saved and restore IOCFG

index c11936e..be4d4bd 100644
@@ -154,11 +154,13 @@ struct piix_map_db {
 
 struct piix_host_priv {
 	const int *map;
+	u32 saved_iocfg;
 	void __iomem *sidpr;
 };
 
 static int piix_init_one(struct pci_dev *pdev,
 			 const struct pci_device_id *ent);
+static void piix_remove_one(struct pci_dev *pdev);
 static int piix_pata_prereset(struct ata_link *link, unsigned long deadline);
 static void piix_set_piomode(struct ata_port *ap, struct ata_device *adev);
 static void piix_set_dmamode(struct ata_port *ap, struct ata_device *adev);

@@ -296,7 +298,7 @@ static struct pci_driver piix_pci_driver = {
 	.name			= DRV_NAME,
 	.id_table		= piix_pci_tbl,
 	.probe			= piix_init_one,
-	.remove			= ata_pci_remove_one,
+	.remove			= piix_remove_one,
 #ifdef CONFIG_PM
 	.suspend		= piix_pci_device_suspend,
 	.resume			= piix_pci_device_resume,

@@ -610,8 +612,9 @@ static const struct ich_laptop ich_laptop[] = {
 static int ich_pata_cable_detect(struct ata_port *ap)
 {
 	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
+	struct piix_host_priv *hpriv = ap->host->private_data;
 	const struct ich_laptop *lap = &ich_laptop[0];
-	u8 tmp, mask;
+	u8 mask;
 
 	/* Check for specials - Acer Aspire 5602WLMi */
 	while (lap->device) {

@@ -625,8 +628,7 @@ static int ich_pata_cable_detect(struct ata_port *ap)
 
 	/* check BIOS cable detect results */
 	mask = ap->port_no == 0 ? PIIX_80C_PRI : PIIX_80C_SEC;
-	pci_read_config_byte(pdev, PIIX_IOCFG, &tmp);
-	if ((tmp & mask) == 0)
+	if ((hpriv->saved_iocfg & mask) == 0)
 		return ATA_CBL_PATA40;
 	return ATA_CBL_PATA80;
 }

@@ -1357,7 +1359,7 @@ static int __devinit piix_init_sidpr(struct ata_host *host)
 	return 0;
 }
 
-static void piix_iocfg_bit18_quirk(struct pci_dev *pdev)
+static void piix_iocfg_bit18_quirk(struct ata_host *host)
 {
 	static const struct dmi_system_id sysids[] = {
 		{

@@ -1374,7 +1376,8 @@ static void piix_iocfg_bit18_quirk(struct pci_dev *pdev)
 
 		{ }	/* terminate list */
 	};
-	u32 iocfg;
+	struct pci_dev *pdev = to_pci_dev(host->dev);
+	struct piix_host_priv *hpriv = host->private_data;
 
 	if (!dmi_check_system(sysids))
 		return;

@@ -1383,12 +1386,11 @@ static void piix_iocfg_bit18_quirk(struct pci_dev *pdev)
 	 * seem to use it to disable a channel.  Clear the bit on the
 	 * affected systems.
 	 */
-	pci_read_config_dword(pdev, PIIX_IOCFG, &iocfg);
-	if (iocfg & (1 << 18)) {
+	if (hpriv->saved_iocfg & (1 << 18)) {
 		dev_printk(KERN_INFO, &pdev->dev,
 			   "applying IOCFG bit18 quirk\n");
-		iocfg &= ~(1 << 18);
-		pci_write_config_dword(pdev, PIIX_IOCFG, iocfg);
+		pci_write_config_dword(pdev, PIIX_IOCFG,
+				       hpriv->saved_iocfg & ~(1 << 18));
 	}
 }
 

@@ -1437,6 +1439,17 @@ static int __devinit piix_init_one(struct pci_dev *pdev,
 	if (rc)
 		return rc;
 
+	hpriv = devm_kzalloc(dev, sizeof(*hpriv), GFP_KERNEL);
+	if (!hpriv)
+		return -ENOMEM;
+
+	/* Save IOCFG, this will be used for cable detection, quirk
+	 * detection and restoration on detach.  This is necessary
+	 * because some ACPI implementations mess up cable related
+	 * bits on _STM.  Reported on kernel bz#11879.
+	 */
+	pci_read_config_dword(pdev, PIIX_IOCFG, &hpriv->saved_iocfg);
+
 	/* ICH6R may be driven by either ata_piix or ahci driver
 	 * regardless of BIOS configuration.  Make sure AHCI mode is
 	 * off.

@@ -1448,10 +1461,6 @@ static int __devinit piix_init_one(struct pci_dev *pdev,
 	}
 
 	/* SATA map init can change port_info, do it before prepping host */
-	hpriv = devm_kzalloc(dev, sizeof(*hpriv), GFP_KERNEL);
-	if (!hpriv)
-		return -ENOMEM;
-
 	if (port_flags & ATA_FLAG_SATA)
 		hpriv->map = piix_init_sata_map(pdev, port_info,
 					piix_map_db_table[ent->driver_data]);

@@ -1470,7 +1479,7 @@ static int __devinit piix_init_one(struct pci_dev *pdev,
 	}
 
 	/* apply IOCFG bit18 quirk */
-	piix_iocfg_bit18_quirk(pdev);
+	piix_iocfg_bit18_quirk(host);
 
 	/* On ICH5, some BIOSen disable the interrupt using the
 	 * PCI_COMMAND_INTX_DISABLE bit added in PCI 2.3.

@@ -1495,6 +1504,16 @@ static int __devinit piix_init_one(struct pci_dev *pdev,
 	return ata_pci_sff_activate_host(host, ata_sff_interrupt, &piix_sht);
 }
 
+static void piix_remove_one(struct pci_dev *pdev)
+{
+	struct ata_host *host = dev_get_drvdata(&pdev->dev);
+	struct piix_host_priv *hpriv = host->private_data;
+
+	pci_write_config_dword(pdev, PIIX_IOCFG, hpriv->saved_iocfg);
+
+	ata_pci_remove_one(pdev);
+}
+
 static int __init piix_init(void)
 {
 	int rc;