提交 cf176e1a 编写于 作者: T Tejun Heo 提交者: Jeff Garzik

[PATCH] libata: implement ata_down_xfermask_limit()

Implement ata_down_xfermask_limit().  This function manipulates
@dev->pio/mwdma/udma_mask such that the next lower transfer mode is
selected.  This will be used to improve ata_bus_probe() failure
handling and later by EH.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>
上级 edbabd86
......@@ -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;
......
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