ata_piix: add workaround for Samsung DB-P70

[linux-2.6-omap-h63xx.git] / drivers / ata / ata_piix.c

diff --git a/drivers/ata/ata_piix.c b/drivers/ata/ata_piix.c
index 54961c0b2c73a58e2dc64313ff95a858bbb262d2..ef8b30d577bd5092484660c05a7cdd75a2c9a803 100644 (file)
--- a/drivers/ata/ata_piix.c
+++ b/drivers/ata/ata_piix.c
@@ -1289,6 +1289,39 @@ static const int *__devinit piix_init_sata_map(struct pci_dev *pdev,
        return map;
 }
 
+static bool piix_no_sidpr(struct ata_host *host)
+{
+       struct pci_dev *pdev = to_pci_dev(host->dev);
+
+       /*
+        * Samsung DB-P70 only has three ATA ports exposed and
+        * curiously the unconnected first port reports link online
+        * while not responding to SRST protocol causing excessive
+        * detection delay.
+        *
+        * Unfortunately, the system doesn't carry enough DMI
+        * information to identify the machine but does have subsystem
+        * vendor and device set.  As it's unclear whether the
+        * subsystem vendor/device is used only for this specific
+        * board, the port can't be disabled solely with the
+        * information; however, turning off SIDPR access works around
+        * the problem.  Turn it off.
+        *
+        * This problem is reported in bnc#441240.
+        *
+        * https://bugzilla.novell.com/show_bug.cgi?id=441420
+        */
+       if (pdev->vendor == PCI_VENDOR_ID_INTEL && pdev->device == 0x2920 &&
+           pdev->subsystem_vendor == PCI_VENDOR_ID_SAMSUNG &&
+           pdev->subsystem_device == 0xb049) {
+               dev_printk(KERN_WARNING, host->dev,
+                          "Samsung DB-P70 detected, disabling SIDPR\n");
+               return true;
+       }
+
+       return false;
+}
+
 static int __devinit piix_init_sidpr(struct ata_host *host)
 {
        struct pci_dev *pdev = to_pci_dev(host->dev);
@@ -1302,6 +1335,10 @@ static int __devinit piix_init_sidpr(struct ata_host *host)
                if (hpriv->map[i] == IDE)
                        return 0;
 
+       /* is it blacklisted? */
+       if (piix_no_sidpr(host))
+               return 0;
+
        if (!(host->ports[0]->flags & PIIX_FLAG_SIDPR))
                return 0;