Commit 02d1d616 authored by Bart Hartgers's avatar Bart Hartgers Committed by Jeff Garzik

sata_via: Correctly setup PIO/DMA for pata slave on vt6421.

Before only the timings for master were set. Datasheet can be found
Surprisingly, a slave drive works without this patch. According to the
datasheet, the controller by default derives the DMA mode from the
Set Features command issued to a drive. Not sure about the PIO
timings, though. The real problem is that the timings for the master
effectively are the ones tuned for the slave. If these support
different UDMA-settings, there is trouble, especially when the slave
supports a higher UDMA than the master.

Anyhow, using the same mechanism for both master and slave seems like
a good idea.
Signed-off-by: default avatarBart Hartgers <>
Acked-by: default avatarTejun Heo <>
Signed-off-by: default avatarJeff Garzik <>
parent 9ffc5da5
......@@ -44,7 +44,7 @@
#include <linux/libata.h>
#define DRV_NAME "sata_via"
#define DRV_VERSION "2.4"
#define DRV_VERSION "2.5"
* vt8251 is different from other sata controllers of VIA. It has two
......@@ -392,14 +392,16 @@ static void vt6421_set_pio_mode(struct ata_port *ap, struct ata_device *adev)
struct pci_dev *pdev = to_pci_dev(ap->host->dev);
static const u8 pio_bits[] = { 0xA8, 0x65, 0x65, 0x31, 0x20 };
pci_write_config_byte(pdev, PATA_PIO_TIMING, pio_bits[adev->pio_mode - XFER_PIO_0]);
pci_write_config_byte(pdev, PATA_PIO_TIMING - adev->devno,
pio_bits[adev->pio_mode - XFER_PIO_0]);
static void vt6421_set_dma_mode(struct ata_port *ap, struct ata_device *adev)
struct pci_dev *pdev = to_pci_dev(ap->host->dev);
static const u8 udma_bits[] = { 0xEE, 0xE8, 0xE6, 0xE4, 0xE2, 0xE1, 0xE0, 0xE0 };
pci_write_config_byte(pdev, PATA_UDMA_TIMING, udma_bits[adev->dma_mode - XFER_UDMA_0]);
pci_write_config_byte(pdev, PATA_UDMA_TIMING - adev->devno,
udma_bits[adev->dma_mode - XFER_UDMA_0]);
static const unsigned int svia_bar_sizes[] = {
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