diff options
| -rw-r--r-- | drivers/scsi/libata-core.c | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c index 3ddfbe1b86c..68fa64d2472 100644 --- a/drivers/scsi/libata-core.c +++ b/drivers/scsi/libata-core.c @@ -65,6 +65,8 @@ static unsigned int ata_dev_init_params(struct ata_port *ap, struct ata_device *dev, u16 heads, u16 sectors); +static int ata_down_xfermask_limit(struct ata_port *ap, struct ata_device *dev, + int force_pio0); static int ata_down_sata_spd_limit(struct ata_port *ap); static int ata_set_mode(struct ata_port *ap, struct ata_device **r_failed_dev); static unsigned int ata_dev_set_xfermode(struct ata_port *ap, @@ -1859,6 +1861,56 @@ int ata_timing_compute(struct ata_device *adev, unsigned short speed, return 0; } +/** + * ata_down_xfermask_limit - adjust dev xfer masks downward + * @ap: Port associated with device @dev + * @dev: Device to adjust xfer masks + * @force_pio0: Force PIO0 + * + * Adjust xfer masks of @dev downward. Note that this function + * does not apply the change. Invoking ata_set_mode() afterwards + * will apply the limit. + * + * LOCKING: + * Inherited from caller. + * + * RETURNS: + * 0 on success, negative errno on failure + */ +static int ata_down_xfermask_limit(struct ata_port *ap, struct ata_device *dev, + int force_pio0) +{ + unsigned long xfer_mask; + int highbit; + + xfer_mask = ata_pack_xfermask(dev->pio_mask, dev->mwdma_mask, + dev->udma_mask); + + if (!xfer_mask) + goto fail; + /* don't gear down to MWDMA from UDMA, go directly to PIO */ + if (xfer_mask & ATA_MASK_UDMA) + xfer_mask &= ~ATA_MASK_MWDMA; + + highbit = fls(xfer_mask) - 1; + xfer_mask &= ~(1 << highbit); + if (force_pio0) + xfer_mask &= 1 << ATA_SHIFT_PIO; + if (!xfer_mask) + goto fail; + + ata_unpack_xfermask(xfer_mask, &dev->pio_mask, &dev->mwdma_mask, + &dev->udma_mask); + + printk(KERN_WARNING "ata%u: dev %u limiting speed to %s\n", + ap->id, dev->devno, ata_mode_string(xfer_mask)); + + return 0; + + fail: + return -EINVAL; +} + static int ata_dev_set_mode(struct ata_port *ap, struct ata_device *dev) { unsigned int err_mask; |