MTD char device access -- return data when ECC errors happen.

This is sane, as the driver returns the real data and the return 
value is for information of NAND aware filesystems. Userspace 
access to raw NAND is usually restricted to debugging tools which 
are aware of the NAND specific problems.
Signed-Off-By: Thomas Gleixner <tglx@linutronix.de>
Signed-Off-By: David Woodhouse <dwmw2@infradead.org>

drivers/mtd/mtdchar.c

 /*
- * $Id: mtdchar.c,v 1.64 2004/08/09 13:59:46 dwmw2 Exp $
+ * $Id: mtdchar.c,v 1.65 2004/09/23 23:45:47 gleixner Exp $
  *
  * Character-device access to raw MTD devices.
  *
@@ -179,7 +179,13 @@ static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t
 			return -ENOMEM;
 		
 		ret = MTD_READ(mtd, *ppos, len, &retlen, kbuf);
-		if (!ret) {
+		/* Nand returns -EBADMSG on ecc errors, but it returns
+		 * the data. For our userspace tools it is important
+		 * to dump areas with ecc errors ! 
+		 * Userspace software which accesses NAND this way
+		 * must be aware of the fact that it deals with NAND
+		 */
+		if (!ret || (ret == -EBADMSG)) {
 			*ppos += retlen;
 			if (copy_to_user(buf, kbuf, retlen)) {
 			        kfree(kbuf);
@@ -198,7 +204,7 @@ static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t
 		
 		kfree(kbuf);
 	}
-	
+
 	return total_retlen;
 } /* mtd_read */