sata_via: Correctly setup PIO/DMA for pata slave on vt6421. (02d1d616) · Commits · 戴 / test

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>

drivers/ata/sata_via.c

+5 −3

Original line number	Diff line number	Diff line
		@@ -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[] = {

Admin message