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

Before only the timings for master were set. Datasheet can be found
here: ftp://ftp.vtbridge.org/Docs/Storage/DS_VT6421A_100_CCPL.PDF
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: Bart Hartgers <bart.hartgers@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
This commit is contained in:
Bart Hartgers 2010-01-17 00:56:54 +01:00 committed by Jeff Garzik
parent 9ffc5da5e1
commit 02d1d6160f
1 changed files with 5 additions and 3 deletions
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8
drivers/ata/sata_via.c
View File

@ -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[] = {