--- drivers/ata/sata_via.c

+++ drivers/ata/sata_via.c

@@ -40,6 +40,8 @@

#include <linux/blkdev.h>

#include <linux/delay.h>

#include <linux/device.h>

+#include <scsi/scsi.h>

+#include <scsi/scsi_cmnd.h>

#include <scsi/scsi_host.h>

#include <linux/libata.h>

@@ -80,6 +82,7 @@ static int vt8251_scr_write(struct ata_l

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 void vt6420_bmdma_start(struct ata_queued_cmd *qc);

static int vt6421_pata_cable_detect(struct ata_port *ap);

static void vt6421_set_pio_mode(struct ata_port *ap, struct ata_device *adev);

static void vt6421_set_dma_mode(struct ata_port *ap, struct ata_device *adev);

@@ -121,6 +124,7 @@ static struct ata_port_operations vt6420

.inherits = &svia_base_ops,

.freeze = svia_noop_freeze,

.prereset = vt6420_prereset,

+ .bmdma_start = vt6420_bmdma_start,

};

static struct ata_port_operations vt6421_pata_ops = {

@@ -377,6 +381,17 @@ static int vt6420_prereset(struct ata_li

return 0;

}

+static void vt6420_bmdma_start(struct ata_queued_cmd *qc)

+{

+ struct ata_port *ap = qc->ap;

+ if ((qc->tf.command == ATA_CMD_PACKET) &&

+ (qc->scsicmd->sc_data_direction == DMA_TO_DEVICE)) {

+ /* Prevents corruption on some ATAPI burners */

+ ata_sff_pause(ap);

+ }

+ ata_bmdma_start(qc);

+}

+

static int vt6421_pata_cable_detect(struct ata_port *ap)

{

struct pci_dev *pdev = to_pci_dev(ap->host->dev);

@@ -558,6 +573,19 @@ static void svia_configure(struct pci_de

tmp8 |= NATIVE_MODE_ALL;

pci_write_config_byte(pdev, SATA_NATIVE_MODE, tmp8);

}

+

+ /*

+ * vt6421 has problems talking to some drives. The following

+ * is the magic fix from Joseph Chan <JosephChan@via.com.tw>.

+ * Please add proper documentation if possible.

+ *

+ * https://bugzilla.kernel.org/show_bug.cgi?id=15173

+ */

+ if (pdev->device == 0x3249) {

+ pci_read_config_byte(pdev, 0x52, &tmp8);

+ tmp8 |= 1 << 2;

+ pci_write_config_byte(pdev, 0x52, tmp8);

+ }

}

static int svia_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)