1 files changed, 20 insertions, 40 deletions

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index acd1162712b1..c95015986c94 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -447,7 +447,8 @@ static const struct ata_port_info ahci_port_info[] = {
         [board_ahci_sb600] =
         {
                 AHCI_HFLAGS     (AHCI_HFLAG_IGN_SERR_INTERNAL |
-                                 AHCI_HFLAG_NO_MSI | AHCI_HFLAG_SECT255),
+                                 AHCI_HFLAG_NO_MSI | AHCI_HFLAG_SECT255 |
+                                 AHCI_HFLAG_32BIT_ONLY),
                 .flags          = AHCI_FLAG_COMMON,
                 .pio_mask       = ATA_PIO4,
                 .udma_mask      = ATA_UDMA6,
@@ -2650,17 +2651,15 @@ static void ahci_p5wdh_workaround(struct ata_host *host)
         }
 }
 
-/*
- * SB600 ahci controller on certain boards can't do 64bit DMA with
- * older BIOS.
- */
-static bool ahci_sb600_32bit_only(struct pci_dev *pdev)
+/* only some SB600 ahci controllers can do 64bit DMA */
+static bool ahci_sb600_enable_64bit(struct pci_dev *pdev)
 {
         static const struct dmi_system_id sysids[] = {
                 /*
                  * The oldest version known to be broken is 0901 and
                  * working is 1501 which was released on 2007-10-26.
-                 * Force 32bit DMA on anything older than 1501.
+                 * Enable 64bit DMA on 1501 and anything newer.
+                 *
                  * Please read bko#9412 for more info.
                  */
                 {
@@ -2672,48 +2671,29 @@ static bool ahci_sb600_32bit_only(struct pci_dev *pdev)
                         },
                         .driver_data = "20071026",      /* yyyymmdd */
                 },
-                /*
-                 * It's yet unknown whether more recent BIOS fixes the
-                 * problem.  Blacklist the whole board for the time
-                 * being.  Please read the following thread for more
-                 * info.
-                 *
-                 * http://thread.gmane.org/gmane.linux.ide/42326
-                 */
-                {
-                        .ident = "Gigabyte GA-MA69VM-S2",
-                        .matches = {
-                                DMI_MATCH(DMI_BOARD_VENDOR,
-                                          "Gigabyte Technology Co., Ltd."),
-                                DMI_MATCH(DMI_BOARD_NAME, "GA-MA69VM-S2"),
-                        },
-                },
                 { }
         };
         const struct dmi_system_id *match;
+        int year, month, date;
+        char buf[9];
 
         match = dmi_first_match(sysids);
         if (pdev->bus->number != 0 || pdev->devfn != PCI_DEVFN(0x12, 0) ||
             !match)
                 return false;
 
-        if (match->driver_data) {
-                int year, month, date;
-                char buf[9];
-
-                dmi_get_date(DMI_BIOS_DATE, &year, &month, &date);
-                snprintf(buf, sizeof(buf), "%04d%02d%02d", year, month, date);
-
-                if (strcmp(buf, match->driver_data) >= 0)
-                        return false;
+        dmi_get_date(DMI_BIOS_DATE, &year, &month, &date);
+        snprintf(buf, sizeof(buf), "%04d%02d%02d", year, month, date);
 
+        if (strcmp(buf, match->driver_data) >= 0) {
+                dev_printk(KERN_WARNING, &pdev->dev, "%s: enabling 64bit DMA\n",
+                           match->ident);
+                return true;
+        } else {
                 dev_printk(KERN_WARNING, &pdev->dev, "%s: BIOS too old, "
                            "forcing 32bit DMA, update BIOS\n", match->ident);
-        } else
-                dev_printk(KERN_WARNING, &pdev->dev, "%s: this board can't "
-                           "do 64bit DMA, forcing 32bit\n", match->ident);
-
-        return true;
+                return false;
+        }
 }
 
 static bool ahci_broken_system_poweroff(struct pci_dev *pdev)
@@ -2926,9 +2906,9 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
         if (board_id == board_ahci_sb700 && pdev->revision >= 0x40)
                 hpriv->flags &= ~AHCI_HFLAG_IGN_SERR_INTERNAL;
 
-        /* apply sb600 32bit only quirk */
-        if (ahci_sb600_32bit_only(pdev))
-                hpriv->flags |= AHCI_HFLAG_32BIT_ONLY;
+        /* only some SB600s can do 64bit DMA */
+        if (ahci_sb600_enable_64bit(pdev))
+                hpriv->flags &= ~AHCI_HFLAG_32BIT_ONLY;
 
         if ((hpriv->flags & AHCI_HFLAG_NO_MSI) || pci_enable_msi(pdev))
                 pci_intx(pdev, 1);