diff options
Diffstat (limited to 'drivers/scsi')
| -rw-r--r-- | drivers/scsi/libata-bmdma.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/drivers/scsi/libata-bmdma.c b/drivers/scsi/libata-bmdma.c index a89e44b21f4d..999725ca8d09 100644 --- a/drivers/scsi/libata-bmdma.c +++ b/drivers/scsi/libata-bmdma.c @@ -700,5 +700,41 @@ err_out: return rc; } +/** + * ata_pci_clear_simplex - attempt to kick device out of simplex + * @pdev: PCI device + * + * Some PCI ATA devices report simplex mode but in fact can be told to + * enter non simplex mode. This implements the neccessary logic to + * perform the task on such devices. Calling it on other devices will + * have -undefined- behaviour. + */ + +int ata_pci_clear_simplex(struct pci_dev *pdev) +{ + unsigned long bmdma = pci_resource_start(pdev, 4); + u8 simplex; + + if (bmdma == 0) + return -ENOENT; + + simplex = inb(bmdma + 0x02); + outb(simplex & 0x60, bmdma + 0x02); + simplex = inb(bmdma + 0x02); + if (simplex & 0x80) + return -EOPNOTSUPP; + return 0; +} + +unsigned long ata_pci_default_filter(const struct ata_port *ap, struct ata_device *adev, unsigned long xfer_mask) +{ + /* Filter out DMA modes if the device has been configured by + the BIOS as PIO only */ + + if (ap->ioaddr.bmdma_addr == 0) + xfer_mask &= ~(ATA_MASK_MWDMA | ATA_MASK_UDMA); + return xfer_mask; +} + #endif /* CONFIG_PCI */ |