Patch "mtd: mtd_oobtest: Handle bitflips during reads" has been added to the 4.15-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    mtd: mtd_oobtest: Handle bitflips during reads

to the 4.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     mtd-mtd_oobtest-handle-bitflips-during-reads.patch
and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Mon Apr  9 10:16:32 CEST 2018
From: Miquel Raynal <miquel.raynal@free-electrons.com>
Date: Thu, 11 Jan 2018 21:39:20 +0100
Subject: mtd: mtd_oobtest: Handle bitflips during reads

From: Miquel Raynal <miquel.raynal@free-electrons.com>


[ Upstream commit 12663b442e5ac5aa3d6097cd3f287c71ba46d26e ]

Reads from NAND devices usually trigger bitflips, this is an expected
behavior. While bitflips are under a given threshold, the MTD core
returns 0. However, when the number of corrected bitflips is above this
same threshold, -EUCLEAN is returned to inform the upper layer that this
block is slightly dying and soon the ECC engine will be overtaken so
actions should be taken to move the data out of it.

This particular condition should not be treated like an error and the
test should continue.

Signed-off-by: Miquel Raynal <miquel.raynal@free-electrons.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/mtd/tests/oobtest.c |   21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

--- a/drivers/mtd/tests/oobtest.c
+++ b/drivers/mtd/tests/oobtest.c
@@ -193,6 +193,9 @@ static int verify_eraseblock(int ebnum)
 		ops.datbuf    = NULL;
 		ops.oobbuf    = readbuf;
 		err = mtd_read_oob(mtd, addr, &ops);
+		if (mtd_is_bitflip(err))
+			err = 0;
+
 		if (err || ops.oobretlen != use_len) {
 			pr_err("error: readoob failed at %#llx\n",
 			       (long long)addr);
@@ -227,6 +230,9 @@ static int verify_eraseblock(int ebnum)
 			ops.datbuf    = NULL;
 			ops.oobbuf    = readbuf;
 			err = mtd_read_oob(mtd, addr, &ops);
+			if (mtd_is_bitflip(err))
+				err = 0;
+
 			if (err || ops.oobretlen != mtd->oobavail) {
 				pr_err("error: readoob failed at %#llx\n",
 						(long long)addr);
@@ -286,6 +292,9 @@ static int verify_eraseblock_in_one_go(i
 
 	/* read entire block's OOB at one go */
 	err = mtd_read_oob(mtd, addr, &ops);
+	if (mtd_is_bitflip(err))
+		err = 0;
+
 	if (err || ops.oobretlen != len) {
 		pr_err("error: readoob failed at %#llx\n",
 		       (long long)addr);
@@ -527,6 +536,9 @@ static int __init mtd_oobtest_init(void)
 	pr_info("attempting to start read past end of OOB\n");
 	pr_info("an error is expected...\n");
 	err = mtd_read_oob(mtd, addr0, &ops);
+	if (mtd_is_bitflip(err))
+		err = 0;
+
 	if (err) {
 		pr_info("error occurred as expected\n");
 		err = 0;
@@ -571,6 +583,9 @@ static int __init mtd_oobtest_init(void)
 		pr_info("attempting to read past end of device\n");
 		pr_info("an error is expected...\n");
 		err = mtd_read_oob(mtd, mtd->size - mtd->writesize, &ops);
+		if (mtd_is_bitflip(err))
+			err = 0;
+
 		if (err) {
 			pr_info("error occurred as expected\n");
 			err = 0;
@@ -615,6 +630,9 @@ static int __init mtd_oobtest_init(void)
 		pr_info("attempting to read past end of device\n");
 		pr_info("an error is expected...\n");
 		err = mtd_read_oob(mtd, mtd->size - mtd->writesize, &ops);
+		if (mtd_is_bitflip(err))
+			err = 0;
+
 		if (err) {
 			pr_info("error occurred as expected\n");
 			err = 0;
@@ -684,6 +702,9 @@ static int __init mtd_oobtest_init(void)
 		ops.datbuf    = NULL;
 		ops.oobbuf    = readbuf;
 		err = mtd_read_oob(mtd, addr, &ops);
+		if (mtd_is_bitflip(err))
+			err = 0;
+
 		if (err)
 			goto out;
 		if (memcmpshow(addr, readbuf, writebuf,


Patches currently in stable-queue which might be from miquel.raynal@free-electrons.com are

queue-4.15/mtd-mtd_oobtest-handle-bitflips-during-reads.patch