Doh.. 

Try changing

       /* Can't enable port 2 yet, see top comments */
        const struct ata_port_info *ppi[] = { &info, };

to

      const struct ata_port_info *ppi[] = { &info, NULL };

Created attachment 23182 [details]
wrap boot log

I used nbd's patch: https://dev.openwrt.org/browser/trunk/target/linux/x86/patches-2.6.31/100-pata_sc1200-wrap.patch?rev=17723 based on Alan's Cox suggestion and everything works fine.  

--- a/drivers/ata/pata_sc1200.c
+++ b/drivers/ata/pata_sc1200.c
@@ -236,7 +236,7 @@
                 .port_ops = &sc1200_port_ops
         };
         /* Can't enable port 2 yet, see top comments */
-        const struct ata_port_info *ppi[] = { &info, };
+        const struct ata_port_info *ppi[] = { &info, &ata_dummy_port_info };
 
         return ata_pci_sff_init_one(dev, ppi, &sc1200_sht, NULL);
 }

This ticket can now close. Thank you.