bcm63xx: nand: fix OOB R/W for non Hamming ECC

Hamming ECC devices do not cover OOB data, as opposed to BCH ECC devices.
Therefore, disabling ECC for all devices is preventing BCH devices from
correctly reading and writing the OOB data.

Signed-off-by: Álvaro Fernández Rojas <[email protected]>

diff --git a/target/linux/bcm63xx/patches-5.4/434-nand-brcmnand-fix-OOB-R-W-with-Hamming-ECC.patch b/target/linux/bcm63xx/patches-5.4/434-nand-brcmnand-fix-OOB-R-W-with-Hamming-ECC.patch
new file mode 100644 (file)
index 0000000..c3bb1ae
--- /dev/null
+++ b/target/linux/bcm63xx/patches-5.4/434-nand-brcmnand-fix-OOB-R-W-with-Hamming-ECC.patch
@@ -0,0 +1,34 @@
+From cf0d2fbaae9e962d91a321de75e0d4f9f9ccbdfe Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?=C3=81lvaro=20Fern=C3=A1ndez=20Rojas?= <[email protected]>
+Date: Thu, 21 Jan 2021 18:17:37 +0100
+Subject: [PATCH] nand: brcmnand: fix OOB R/W with Hamming ECC
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Hamming ECC doesn't cover the OOB data, so reading or writing OOB shall
+always be done without ECC enabled.
+This is a problem when adding JFFS2 cleanmarkers to erased blocks. When JFFS2
+clenmarkers are added to the OOB with ECC enabled, OOB bytes will be changed
+from ff ff ff to 00 00 00, reporting incorrect ECC errors.
+
+Signed-off-by: Álvaro Fernández Rojas <[email protected]>
+---
+ drivers/mtd/nand/raw/brcmnand/brcmnand.c | 6 ++++++
+ 1 file changed, 6 insertions(+)
+
+--- a/drivers/mtd/nand/raw/brcmnand/brcmnand.c
++++ b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
+@@ -2426,6 +2426,12 @@ static int brcmnand_attach_chip(struct n
+ 
+       ret = brcmstb_choose_ecc_layout(host);
+ 
++      /* If OOB is written with ECC enabled it will cause ECC errors */
++      if (is_hamming_ecc(host->ctrl, &host->hwcfg)) {
++              chip->ecc.write_oob = brcmnand_write_oob_raw;
++              chip->ecc.read_oob = brcmnand_read_oob_raw;
++      }
++
+       return ret;
+ }
+ 

diff --git a/target/linux/bcm63xx/patches-5.4/434-nand-raw-use-write_oob_raw-for-MTD_OPS_AUTO_OOB-mode.patch b/target/linux/bcm63xx/patches-5.4/434-nand-raw-use-write_oob_raw-for-MTD_OPS_AUTO_OOB-mode.patch
deleted file mode 100644 (file)
index cf4322f..0000000
--- a/target/linux/bcm63xx/patches-5.4/434-nand-raw-use-write_oob_raw-for-MTD_OPS_AUTO_OOB-mode.patch
+++ /dev/null
@@ -1,11 +0,0 @@
---- a/drivers/mtd/nand/raw/nand_base.c
-+++ b/drivers/mtd/nand/raw/nand_base.c
-@@ -488,7 +488,7 @@ static int nand_do_write_oob(struct nand
- 
-       nand_fill_oob(chip, ops->oobbuf, ops->ooblen, ops);
- 
--      if (ops->mode == MTD_OPS_RAW)
-+      if (ops->mode == MTD_OPS_AUTO_OOB || ops->mode == MTD_OPS_RAW)
-               status = chip->ecc.write_oob_raw(chip, page & chip->pagemask);
-       else
-               status = chip->ecc.write_oob(chip, page & chip->pagemask);