pata_cm64x: fix boot crash on parisc

[linux-flexiantxendom0-natty.git] / drivers / ata / pata_cmd64x.c

diff --git a/drivers/ata/pata_cmd64x.c b/drivers/ata/pata_cmd64x.c
index 905ff76..635a759 100644 (file)
--- a/drivers/ata/pata_cmd64x.c
+++ b/drivers/ata/pata_cmd64x.c
@@ -41,6 +41,9 @@
 enum {
        CFR             = 0x50,
                CFR_INTR_CH0  = 0x04,
+       CNTRL           = 0x51,
+               CNTRL_CH0     = 0x04,
+               CNTRL_CH1     = 0x08,
        CMDTIM          = 0x52,
        ARTTIM0         = 0x53,
        DRWTIM0         = 0x54,
@@ -328,9 +331,19 @@ static int cmd64x_init_one(struct pci_dev *pdev, const struct pci_device_id *id)
                        .port_ops = &cmd648_port_ops
                }
        };
-       const struct ata_port_info *ppi[] = { &cmd_info[id->driver_data], NULL };
-       u8 mrdmode;
+       const struct ata_port_info *ppi[] = {
+               &cmd_info[id->driver_data],
+               &cmd_info[id->driver_data],
+               NULL
+       };
+       u8 mrdmode, reg;
        int rc;
+       struct pci_dev *bridge = pdev->bus->self;
+       /* mobility split bridges don't report enabled ports correctly */
+       int port_ok = !(bridge && bridge->vendor ==
+                       PCI_VENDOR_ID_MOBILITY_ELECTRONICS);
+       /* all (with exceptions below) apart from 643 have CNTRL_CH0 bit */
+       int cntrl_ch0_ok = (id->driver_data != 0);
 
        rc = pcim_enable_device(pdev);
        if (rc)
@@ -341,11 +354,18 @@ static int cmd64x_init_one(struct pci_dev *pdev, const struct pci_device_id *id)
 
        if (pdev->device == PCI_DEVICE_ID_CMD_646) {
                /* Does UDMA work ? */
-               if (pdev->revision > 4)
+               if (pdev->revision > 4) {
                        ppi[0] = &cmd_info[2];
+                       ppi[1] = &cmd_info[2];
+               }
                /* Early rev with other problems ? */
-               else if (pdev->revision == 1)
+               else if (pdev->revision == 1) {
                        ppi[0] = &cmd_info[3];
+                       ppi[1] = &cmd_info[3];
+               }
+               /* revs 1,2 have no CNTRL_CH0 */
+               if (pdev->revision < 3)
+                       cntrl_ch0_ok = 0;
        }
 
        pci_write_config_byte(pdev, PCI_LATENCY_TIMER, 64);
@@ -354,6 +374,20 @@ static int cmd64x_init_one(struct pci_dev *pdev, const struct pci_device_id *id)
        mrdmode |= 0x02;        /* Memory read line enable */
        pci_write_config_byte(pdev, MRDMODE, mrdmode);
 
+       /* check for enabled ports */
+       pci_read_config_byte(pdev, CNTRL, &reg);
+       if (!port_ok)
+               dev_printk(KERN_NOTICE, &pdev->dev, "Mobility Bridge detected, ignoring CNTRL port enable/disable\n");
+       if (port_ok && cntrl_ch0_ok && !(reg & CNTRL_CH0)) {
+               dev_printk(KERN_NOTICE, &pdev->dev, "Primary port is disabled\n");
+               ppi[0] = &ata_dummy_port_info;
+
+       }
+       if (port_ok && !(reg & CNTRL_CH1)) {
+               dev_printk(KERN_NOTICE, &pdev->dev, "Secondary port is disabled\n");
+               ppi[1] = &ata_dummy_port_info;
+       }
+
        /* Force PIO 0 here.. */
 
        /* PPC specific fixup copied from old driver */