sata_mv add temporary 3 second init delay for SiliconImage PMs

sata_mv does not yet fully support hotplug (coming soon, though).
This means that the driver may not find a Silicon Image port-multiplier
when first loaded, because those devices take in exceess of 3 seconds
to sync up the SATA PHY (most devices do this in mere microseconds).

So, as a short-term interim measure, here we insert a 3-second pause
on initial driver load, once per controller board (not once per port!),
to allow the Silicon Image port-multipliers to be detected later.

This will be removed again (soon!) once hotplug is fully implemented/working.
Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

drivers/ata/sata_mv.c

@@ -2105,6 +2105,13 @@ static int mv6_reset_hc(struct mv_host_priv *hpriv, void __iomem *mmio,
 		printk(KERN_ERR DRV_NAME ": can't clear global reset\n");
 		rc = 1;
 	}
+	/*
+	 * Temporary: wait 3 seconds before port-probing can happen,
+	 * so that we don't miss finding sleepy SilXXXX port-multipliers.
+	 * This can go away once hotplug is fully/correctly implemented.
+	 */
+	if (rc == 0)
+		msleep(3000);
 done:
 	return rc;
 }