ata_piix: don't attach to ICH6M in ahci mode

ata_piix when attached to ICH6M in AHCI mode doesn't provide any
benefit over using ahci and has detection problems.  Don't let
ata_piix claim ICH6M if it's in AHCI mode.

This change makes ICH6R the only one which ata_piix can attach to even
when it's in ahci mode which is necessary as some devices don't work
properly under ahci mode.  Drop PIIX_FLAG_AHCI and match the
controller directly so that piix_disable_ahci() is called only for it.

This change makes PIIX_SCC no longer used and it gets dropped too.

This fixes bz 9491.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Robert M. Albrecht <romal@gmx.de>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 20 insertions, 23 deletions

diff --git a/drivers/ata/ata_piix.c b/drivers/ata/ata_piix.c
index eafb984313f6..e6bf4fd51794 100644
--- a/drivers/ata/ata_piix.c
+++ b/drivers/ata/ata_piix.c
@@ -100,13 +100,11 @@ enum {
         PIIX_IOCFG              = 0x54, /* IDE I/O configuration register */
         ICH5_PMR                = 0x90, /* port mapping register */
         ICH5_PCS                = 0x92, /* port control and status */
-        PIIX_SCC                = 0x0A, /* sub-class code register */
         PIIX_SIDPR_BAR          = 5,
         PIIX_SIDPR_LEN          = 16,
         PIIX_SIDPR_IDX          = 0,
         PIIX_SIDPR_DATA         = 4,
 
-        PIIX_FLAG_AHCI          = (1 << 27), /* AHCI possible */
         PIIX_FLAG_CHECKINTR     = (1 << 28), /* make sure PCI INTx enabled */
         PIIX_FLAG_SIDPR         = (1 << 29), /* SATA idx/data pair regs */
 
@@ -238,8 +236,10 @@ static const struct pci_device_id piix_pci_tbl[] = {
         { 0x8086, 0x2651, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich6_sata },
         /* 82801FR/FRW (ICH6R/ICH6RW) */
         { 0x8086, 0x2652, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich6_sata_ahci },
-        /* 82801FBM ICH6M (ICH6R with only port 0 and 2 implemented) */
-        { 0x8086, 0x2653, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich6m_sata_ahci },
+        /* 82801FBM ICH6M (ICH6R with only port 0 and 2 implemented).
+         * Attach iff the controller is in IDE mode. */
+        { 0x8086, 0x2653, PCI_ANY_ID, PCI_ANY_ID,
+          PCI_CLASS_STORAGE_IDE << 8, 0xffff00, ich6m_sata_ahci },
         /* 82801GB/GR/GH (ICH7, identical to ICH6) */
         { 0x8086, 0x27c0, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich6_sata_ahci },
         /* 2801GBM/GHM (ICH7M, identical to ICH6M) */
@@ -494,7 +494,7 @@ static struct ata_port_info piix_port_info[] = {
 
         [ich6_sata_ahci] =
         {
-                .flags          = PIIX_SATA_FLAGS | PIIX_FLAG_AHCI,
+                .flags          = PIIX_SATA_FLAGS,
                 .pio_mask       = 0x1f, /* pio0-4 */
                 .mwdma_mask     = 0x07, /* mwdma0-2 */
                 .udma_mask      = ATA_UDMA6,
@@ -503,7 +503,7 @@ static struct ata_port_info piix_port_info[] = {
 
         [ich6m_sata_ahci] =
         {
-                .flags          = PIIX_SATA_FLAGS | PIIX_FLAG_AHCI,
+                .flags          = PIIX_SATA_FLAGS,
                 .pio_mask       = 0x1f, /* pio0-4 */
                 .mwdma_mask     = 0x07, /* mwdma0-2 */
                 .udma_mask      = ATA_UDMA6,
@@ -512,8 +512,7 @@ static struct ata_port_info piix_port_info[] = {
 
         [ich8_sata_ahci] =
         {
-                .flags          = PIIX_SATA_FLAGS | PIIX_FLAG_AHCI |
-                                  PIIX_FLAG_SIDPR,
+                .flags          = PIIX_SATA_FLAGS | PIIX_FLAG_SIDPR,
                 .pio_mask       = 0x1f, /* pio0-4 */
                 .mwdma_mask     = 0x07, /* mwdma0-2 */
                 .udma_mask      = ATA_UDMA6,
@@ -522,8 +521,7 @@ static struct ata_port_info piix_port_info[] = {
 
         [ich8_2port_sata] =
         {
-                .flags          = PIIX_SATA_FLAGS | PIIX_FLAG_AHCI |
-                                  PIIX_FLAG_SIDPR,
+                .flags          = PIIX_SATA_FLAGS | PIIX_FLAG_SIDPR,
                 .pio_mask       = 0x1f, /* pio0-4 */
                 .mwdma_mask     = 0x07, /* mwdma0-2 */
                 .udma_mask      = ATA_UDMA6,
@@ -532,7 +530,7 @@ static struct ata_port_info piix_port_info[] = {
 
         [tolapai_sata_ahci] =
         {
-                .flags          = PIIX_SATA_FLAGS | PIIX_FLAG_AHCI,
+                .flags          = PIIX_SATA_FLAGS,
                 .pio_mask       = 0x1f, /* pio0-4 */
                 .mwdma_mask     = 0x07, /* mwdma0-2 */
                 .udma_mask      = ATA_UDMA6,
@@ -541,8 +539,7 @@ static struct ata_port_info piix_port_info[] = {
 
         [ich8m_apple_sata_ahci] =
         {
-                .flags          = PIIX_SATA_FLAGS | PIIX_FLAG_AHCI |
-                                  PIIX_FLAG_SIDPR,
+                .flags          = PIIX_SATA_FLAGS | PIIX_FLAG_SIDPR,
                 .pio_mask       = 0x1f, /* pio0-4 */
                 .mwdma_mask     = 0x07, /* mwdma0-2 */
                 .udma_mask      = ATA_UDMA6,
@@ -1488,6 +1485,16 @@ static int __devinit piix_init_one(struct pci_dev *pdev,
         if (rc)
                 return rc;
 
+        /* ICH6R may be driven by either ata_piix or ahci driver
+         * regardless of BIOS configuration.  Make sure AHCI mode is
+         * off.
+         */
+        if (pdev->vendor == PCI_VENDOR_ID_INTEL && pdev->device == 0x2652) {
+                int rc = piix_disable_ahci(pdev);
+                if (rc)
+                        return rc;
+        }
+
         /* SATA map init can change port_info, do it before prepping host */
         hpriv = devm_kzalloc(dev, sizeof(*hpriv), GFP_KERNEL);
         if (!hpriv)
@@ -1503,16 +1510,6 @@ static int __devinit piix_init_one(struct pci_dev *pdev,
         host->private_data = hpriv;
 
         /* initialize controller */
-        if (port_flags & PIIX_FLAG_AHCI) {
-                u8 tmp;
-                pci_read_config_byte(pdev, PIIX_SCC, &tmp);
-                if (tmp == PIIX_AHCI_DEVICE) {
-                        rc = piix_disable_ahci(pdev);
-                        if (rc)
-                                return rc;
-                }
-        }
-
         if (port_flags & ATA_FLAG_SATA) {
                 piix_init_pcs(host, piix_map_db_table[ent->driver_data]);
                 piix_init_sidpr(host);