From: Engling, Uwe <Uwe.Engling@ise.de>
Date: Tue, 10 Oct 2017 14:20:55 +0000 (+0000)
Subject: jffs2: ECC corrected nand data is ignored
X-Git-Url: http://git.dujemihanovic.xyz/?a=commitdiff_plain;h=41ba7f525fa21941dee062b87adbbd7dde72f32f;p=u-boot.git

jffs2: ECC corrected nand data is ignored

Hello,

I ran into a problem with the JFFS2 filesystem driver implemented in U-Boot.

I've got a NAND device that has correctable ECC errors (corrected somewhere in mtd/nand/nand_base.c).
The NAND driver tells the filesystem layer (jffs2_1pass.c) above that there occurred correctable ECC errors and returns with a "value > 0".
The JFFS2 driver recognizes the corrected ECC errors as real error and skips this block because the only accepts a "return value == 0" as correct.

This problem exists for over 8 years (I checked version 2010.09) so I'm a little bit worried that I interpreted something wrong or didn't get the whole context.

Can someone confirm this bug (and the bugfix) in the u-boot jffs2 driver?

There was a mail in 2012 that mentioned the same problem, but there was no patch:
http://u-boot.10912.n7.nabble.com/JFFS2-seems-to-drop-nand-data-with-ECC-corrections-td142008.html
Sometime after this discussion the return value of nand_read() changed from -EUCLEAN as correctable ECC error to a positive value with the count of ECC corrected errors.

With kind reguards,
Uwe Engling
---

diff --git a/fs/jffs2/jffs2_1pass.c b/fs/jffs2/jffs2_1pass.c
index 4c6dfbf249..6bf1943958 100644
--- a/fs/jffs2/jffs2_1pass.c
+++ b/fs/jffs2/jffs2_1pass.c
@@ -201,7 +201,7 @@ static int read_nand_cached(u32 off, u32 size, u_char *buf)
 
 			retlen = NAND_CACHE_SIZE;
 			if (nand_read(mtd, nand_cache_off,
-				      &retlen, nand_cache) != 0 ||
+				      &retlen, nand_cache) < 0 ||
 					retlen != NAND_CACHE_SIZE) {
 				printf("read_nand_cached: error reading nand off %#x size %d bytes\n",
 						nand_cache_off, NAND_CACHE_SIZE);
@@ -300,7 +300,7 @@ static int read_onenand_cached(u32 off, u32 size, u_char *buf)
 
 			retlen = ONENAND_CACHE_SIZE;
 			if (onenand_read(&onenand_mtd, onenand_cache_off, retlen,
-						&retlen, onenand_cache) != 0 ||
+						&retlen, onenand_cache) < 0 ||
 					retlen != ONENAND_CACHE_SIZE) {
 				printf("read_onenand_cached: error reading nand off %#x size %d bytes\n",
 					onenand_cache_off, ONENAND_CACHE_SIZE);