Re: [PATCH 15/15] libata: consider disabled devices in ata_dev_xfermask()

[Jeff Garzik <jgarzik@pobox.com>]

Tejun Heo wrote:
> ata_bus_probe() now marks failed devices properly and leaves
> meaningful transfer mode masks.  This patch makes ata_dev_xfermask()
> consider disable devices when determining PIO mode to avoid violating
> device selection timing.
> 
> While at it, move port-wide resttriction out of device iteration loop
> and try to make the function look a bit prettier.
> 
> Signed-off-by: Tejun Heo <htejun@gmail.com>
> 
> ---
> 
>  drivers/scsi/libata-core.c |   34 +++++++++++++++++++++++-----------
>  1 files changed, 23 insertions(+), 11 deletions(-)
> 
> 523b496b7614981773c2c14259bbca4a7ba3a3e8
> diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
> index ac2ca31..0d72792 100644
> --- a/drivers/scsi/libata-core.c
> +++ b/drivers/scsi/libata-core.c
> @@ -2902,23 +2902,34 @@ static void ata_dev_xfermask(struct ata_
>  	unsigned long xfer_mask;
>  	int i;
>  
> -	xfer_mask = ata_pack_xfermask(ap->pio_mask, ap->mwdma_mask,
> -				      ap->udma_mask);
> +	xfer_mask = ata_pack_xfermask(ap->pio_mask,
> +				      ap->mwdma_mask, ap->udma_mask);
> +
> +	/* Apply cable rule here.  Don't apply it early because when
> +	 * we handle hot plug the cable type can itself change.
> +	 */
> +	if (ap->cbl == ATA_CBL_PATA40)
> +		xfer_mask &= ~(0xF8 << ATA_SHIFT_UDMA);

ACK, though I wonder if moving the above code to its current position 
violates "early" described in the comment.

	Jeff