[MTD] NAND Signal that a bitflip was corrected by ECC

Return -EUCLEAN on read when a bitflip was detected and corrected, so the
clients can react and eventually copy the affected block to a spare one.
Make all in kernel users aware of the change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c
index 7522fc3a2827..a48210d58b92 100644
--- a/drivers/mtd/mtdchar.c
+++ b/drivers/mtd/mtdchar.c
@@ -199,10 +199,13 @@ static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t
                 /* Nand returns -EBADMSG on ecc errors, but it returns
                  * the data. For our userspace tools it is important
                  * to dump areas with ecc errors !
+                 * For kernel internal usage it also might return -EUCLEAN
+                 * to signal the caller that a bitflip has occured and has
+                 * been corrected by the ECC algorithm.
                  * Userspace software which accesses NAND this way
                  * must be aware of the fact that it deals with NAND
                  */
-                if (!ret || (ret == -EBADMSG)) {
+                if (!ret || (ret == -EUCLEAN) || (ret == -EBADMSG)) {
                         *ppos += retlen;
                         if (copy_to_user(buf, kbuf, retlen)) {
                                 kfree(kbuf);