1 files changed, 32 insertions, 3 deletions

diff --git a/drivers/ata/sata_via.c b/drivers/ata/sata_via.c
index 1cfa74535d91..5b72e734300a 100644
--- a/drivers/ata/sata_via.c
+++ b/drivers/ata/sata_via.c
@@ -70,6 +70,7 @@ enum {
 static int svia_init_one(struct pci_dev *pdev, const struct pci_device_id *ent);
 static int svia_scr_read(struct ata_link *link, unsigned int sc_reg, u32 *val);
 static int svia_scr_write(struct ata_link *link, unsigned int sc_reg, u32 val);
+static void svia_tf_load(struct ata_port *ap, const struct ata_taskfile *tf);
 static void svia_noop_freeze(struct ata_port *ap);
 static int vt6420_prereset(struct ata_link *link, unsigned long deadline);
 static int vt6421_pata_cable_detect(struct ata_port *ap);
@@ -103,21 +104,26 @@ static struct scsi_host_template svia_sht = {
         ATA_BMDMA_SHT(DRV_NAME),
 };
 
-static struct ata_port_operations vt6420_sata_ops = {
+static struct ata_port_operations svia_base_ops = {
         .inherits               = &ata_bmdma_port_ops,
+        .sff_tf_load            = svia_tf_load,
+};
+
+static struct ata_port_operations vt6420_sata_ops = {
+        .inherits               = &svia_base_ops,
         .freeze                 = svia_noop_freeze,
         .prereset               = vt6420_prereset,
 };
 
 static struct ata_port_operations vt6421_pata_ops = {
-        .inherits               = &ata_bmdma_port_ops,
+        .inherits               = &svia_base_ops,
         .cable_detect           = vt6421_pata_cable_detect,
         .set_piomode            = vt6421_set_pio_mode,
         .set_dmamode            = vt6421_set_dma_mode,
 };
 
 static struct ata_port_operations vt6421_sata_ops = {
-        .inherits               = &ata_bmdma_port_ops,
+        .inherits               = &svia_base_ops,
         .scr_read               = svia_scr_read,
         .scr_write              = svia_scr_write,
 };
@@ -168,6 +174,29 @@ static int svia_scr_write(struct ata_link *link, unsigned int sc_reg, u32 val)
         return 0;
 }
 
+/**
+ *      svia_tf_load - send taskfile registers to host controller
+ *      @ap: Port to which output is sent
+ *      @tf: ATA taskfile register set
+ *
+ *      Outputs ATA taskfile to standard ATA host controller.
+ *
+ *      This is to fix the internal bug of via chipsets, which will
+ *      reset the device register after changing the IEN bit on ctl
+ *      register.
+ */
+static void svia_tf_load(struct ata_port *ap, const struct ata_taskfile *tf)
+{
+        struct ata_taskfile ttf;
+
+        if (tf->ctl != ap->last_ctl)  {
+                ttf = *tf;
+                ttf.flags |= ATA_TFLAG_DEVICE;
+                tf = &ttf;
+        }
+        ata_sff_tf_load(ap, tf);
+}
+
 static void svia_noop_freeze(struct ata_port *ap)
 {
         /* Some VIA controllers choke if ATA_NIEN is manipulated in