libata: relocate forcing PIO0 on reset

Forcing PIO0 on reset was done inside ata_bus_softreset(), which is a
bit out of place as it should be applied to all resets - hard, soft
and implementation which don't use ata_bus_softreset().  Relocate it
such that...

* For new EH, it's done in ata_eh_reset() before calling prereset.

* For old EH, it's done before calling ap->ops->phy_reset() in
  ata_bus_probe().

This makes PIO0 forced after all resets.  Another difference is that
reset itself is done after PIO0 is forced.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

drivers/ata/libata-eh.c

@@ -2083,6 +2083,25 @@ int ata_eh_reset(struct ata_link *link, int classify,
 
 	ata_eh_about_to_do(link, NULL, ehc->i.action & ATA_EH_RESET_MASK);
 
+	ata_link_for_each_dev(dev, link) {
+		/* If we issue an SRST then an ATA drive (not ATAPI)
+		 * may change configuration and be in PIO0 timing. If
+		 * we do a hard reset (or are coming from power on)
+		 * this is true for ATA or ATAPI. Until we've set a
+		 * suitable controller mode we should not touch the
+		 * bus as we may be talking too fast.
+		 */
+		dev->pio_mode = XFER_PIO_0;
+
+		/* If the controller has a pio mode setup function
+		 * then use it to set the chipset to rights. Don't
+		 * touch the DMA setup as that will be dealt with when
+		 * configuring devices.
+		 */
+		if (ap->ops->set_piomode)
+			ap->ops->set_piomode(ap, dev);
+	}
+
 	/* Determine which reset to use and record in ehc->i.action.
 	 * prereset() may examine and modify it.
 	 */