1 files changed, 44 insertions, 12 deletions

diff --git a/drivers/ata/pata_via.c b/drivers/ata/pata_via.c
index 88984b803d6d..0d97890af681 100644
--- a/drivers/ata/pata_via.c
+++ b/drivers/ata/pata_via.c
@@ -303,14 +303,21 @@ static void via_do_set_mode(struct ata_port *ap, struct ata_device *adev, int mo
         }
 
         /* Set UDMA unless device is not UDMA capable */
-        if (udma_type && t.udma) {
-                u8 cable80_status;
+        if (udma_type) {
+                u8 udma_etc;
 
-                /* Get 80-wire cable detection bit */
-                pci_read_config_byte(pdev, 0x50 + offset, &cable80_status);
-                cable80_status &= 0x10;
+                pci_read_config_byte(pdev, 0x50 + offset, &udma_etc);
 
-                pci_write_config_byte(pdev, 0x50 + offset, ut | cable80_status);
+                /* clear transfer mode bit */
+                udma_etc &= ~0x20;
+
+                if (t.udma) {
+                        /* preserve 80-wire cable detection bit */
+                        udma_etc &= 0x10;
+                        udma_etc |= ut;
+                }
+
+                pci_write_config_byte(pdev, 0x50 + offset, udma_etc);
         }
 }
 
@@ -337,6 +344,32 @@ static void via_set_dmamode(struct ata_port *ap, struct ata_device *adev)
 }
 
 /**
+ *      via_mode_filter         -       filter buggy device/mode pairs
+ *      @dev: ATA device
+ *      @mask: Mode bitmask
+ *
+ *      We need to apply some minimal filtering for old controllers and at least
+ *      one breed of Transcend SSD. Return the updated mask.
+ */
+
+static unsigned long via_mode_filter(struct ata_device *dev, unsigned long mask)
+{
+        struct ata_host *host = dev->link->ap->host;
+        const struct via_isa_bridge *config = host->private_data;
+        unsigned char model_num[ATA_ID_PROD_LEN + 1];
+
+        if (config->id == PCI_DEVICE_ID_VIA_82C586_0) {
+                ata_id_c_string(dev->id, model_num, ATA_ID_PROD, sizeof(model_num));
+                if (strcmp(model_num, "TS64GSSD25-M") == 0) {
+                        ata_dev_printk(dev, KERN_WARNING,
+        "disabling UDMA mode due to reported lockups with this device.\n");
+                        mask &= ~ ATA_MASK_UDMA;
+                }
+        }
+        return ata_bmdma_mode_filter(dev, mask);
+}
+
+/**
  *      via_tf_load - send taskfile registers to host controller
  *      @ap: Port to which output is sent
  *      @tf: ATA taskfile register set
@@ -427,6 +460,7 @@ static struct ata_port_operations via_port_ops = {
         .prereset       = via_pre_reset,
         .sff_tf_load    = via_tf_load,
         .port_start     = via_port_start,
+        .mode_filter    = via_mode_filter,
 };
 
 static struct ata_port_operations via_port_ops_noirq = {
@@ -526,7 +560,7 @@ static int via_init_one(struct pci_dev *pdev, const struct pci_device_id *id)
                 .port_ops = &via_port_ops
         };
         const struct ata_port_info *ppi[] = { NULL, NULL };
-        struct pci_dev *isa = NULL;
+        struct pci_dev *isa;
         const struct via_isa_bridge *config;
         static int printed_version;
         u8 enable;
@@ -551,15 +585,13 @@ static int via_init_one(struct pci_dev *pdev, const struct pci_device_id *id)
                 if ((isa = pci_get_device(PCI_VENDOR_ID_VIA +
                         !!(config->flags & VIA_BAD_ID),
                         config->id, NULL))) {
+                        u8 rev = isa->revision;
+                        pci_dev_put(isa);
 
-                        if (isa->revision >= config->rev_min &&
-                            isa->revision <= config->rev_max)
+                        if (rev >= config->rev_min && rev <= config->rev_max)
                                 break;
-                        pci_dev_put(isa);
                 }
 
-        pci_dev_put(isa);
-
         if (!(config->flags & VIA_NO_ENABLES)) {
                 /* 0x40 low bits indicate enabled channels */
                 pci_read_config_byte(pdev, 0x40 , &enable);