libata: no need to speed down if already at PIO0

After reset, transfer mode is always PIO0 regardless of
dev->xfer_mask.  Check dev->pio_mode before trying to slow down after
configuration failure.  This prevents bogus speed down before device
is actually configured.

Signed-off-by: Tejun Heo <[email protected]>
Acked-by: Alan Cox <[email protected]>
Signed-off-by: Jeff Garzik <[email protected]>
1 file changed