NAND: show manufacturer and device ID for unknown chips

When the NAND part is not supported, it is useful to show the manufacturer
and device ID to help debugging and reporting.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 7171bdd..ed1c9c9 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -2652,8 +2652,12 @@
 		}
 	}
 
-	if (!type)
+	if (!type) {
+		printk(KERN_INFO "%s: unknown NAND device: Manufacturer ID:"
+		       " 0x%02x, Chip ID: 0x%02x\n", __func__,
+		       *maf_id, dev_id);
 		return ERR_PTR(-ENODEV);
+	}
 
 	if (!mtd->name)
 		mtd->name = type->name;