[PATCH 4/7] mtd/spinand: sync core spinand code with linux-5.10.118

[mikhail . kshevetskiy]

From: Mikhail Kshevetskiy <mikhail.kshevets...@iopsys.eu>

Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevets...@iopsys.eu>
---
 drivers/mtd/nand/spi/core.c | 24 ++++++++++++++----------
 1 file changed, 14 insertions(+), 10 deletions(-)

diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c
index e42c061049..d0c7d82010 100644
--- a/drivers/mtd/nand/spi/core.c
+++ b/drivers/mtd/nand/spi/core.c
@@ -326,6 +326,13 @@ static int spinand_write_to_cache_op(struct spinand_device 
*spinand,
        u16 column = 0;
        int ret;
 
+       /*
+        * Looks like PROGRAM LOAD (AKA write cache) does not necessarily reset
+        * the cache content to 0xFF (depends on vendor implementation), so we
+        * must fill the page cache entirely even if we only want to program
+        * the data portion of the page, otherwise we might corrupt the BBM or
+        * user data previously programmed in OOB area.
+        */
        memset(spinand->databuf, 0xff,
               nanddev_page_size(nand) +
               nanddev_per_page_oobsize(nand));
@@ -598,12 +605,12 @@ static int spinand_mtd_read(struct mtd_info *mtd, loff_t 
from,
                if (ret == -EBADMSG) {
                        ecc_failed = true;
                        mtd->ecc_stats.failed++;
-                       ret = 0;
                } else {
                        mtd->ecc_stats.corrected += ret;
                        max_bitflips = max_t(unsigned int, max_bitflips, ret);
                }
 
+               ret = 0;
                ops->retlen += iter.req.datalen;
                ops->oobretlen += iter.req.ooblen;
        }
@@ -669,16 +676,9 @@ static bool spinand_isbad(struct nand_device *nand, const 
struct nand_pos *pos)
                .oobbuf.in = marker,
                .mode = MTD_OPS_RAW,
        };
-       int ret;
-
-       ret = spinand_select_target(spinand, pos->target);
-       if (ret)
-               return ret;
-
-       ret = spinand_read_page(spinand, &req, false);
-       if (ret)
-               return ret;
 
+       spinand_select_target(spinand, pos->target);
+       spinand_read_page(spinand, &req, false);
        if (marker[0] != 0xff || marker[1] != 0xff)
                return true;
 
@@ -722,6 +722,10 @@ static int spinand_markbad(struct nand_device *nand, const 
struct nand_pos *pos)
        if (ret)
                return ret;
 
+       ret = spinand_write_enable_op(spinand);
+       if (ret)
+               return ret;
+
        return spinand_write_page(spinand, &req);
 }
 
-- 
2.35.1