diff options
| -rw-r--r-- | drivers/ide/via82cxxx.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/drivers/ide/via82cxxx.c b/drivers/ide/via82cxxx.c index 3db35b0142dc..fbecf8ea8207 100644 --- a/drivers/ide/via82cxxx.c +++ b/drivers/ide/via82cxxx.c @@ -146,10 +146,25 @@ static void via_set_speed(ide_hwif_t *hwif, u8 dn, struct ide_timing *timing) case ATA_UDMA4: t = timing->udma ? (0xe8 | (clamp_val(timing->udma, 2, 9) - 2)) : 0x0f; break; case ATA_UDMA5: t = timing->udma ? (0xe0 | (clamp_val(timing->udma, 2, 9) - 2)) : 0x07; break; case ATA_UDMA6: t = timing->udma ? (0xe0 | (clamp_val(timing->udma, 2, 9) - 2)) : 0x07; break; - default: return; } - pci_write_config_byte(dev, VIA_UDMA_TIMING + (3 - dn), t); + /* Set UDMA unless device is not UDMA capable */ + if (vdev->via_config->udma_mask) { + u8 udma_etc; + + pci_read_config_byte(dev, VIA_UDMA_TIMING + 3 - dn, &udma_etc); + + /* clear transfer mode bit */ + udma_etc &= ~0x20; + + if (timing->udma) { + /* preserve 80-wire cable detection bit */ + udma_etc &= 0x10; + udma_etc |= t; + } + + pci_write_config_byte(dev, VIA_UDMA_TIMING + 3 - dn, udma_etc); + } } /** |