mtd: nand: use nand_check_erased_ecc_chunk in default ECC read functions
The default NAND read functions are relying on the underlying controller
driver to correct bitflips, but some of those controllers cannot properly
fix bitflips in erased pages.
Check for bitflips in erased pages in default core functions if the driver
delegated the this check by setting the NAND_ECC_GENERIC_ERASED_CHECK flag.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: Franklin S Cooper Jr. <fcooper@ti.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 50514f2..f2c8ff3 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -1426,6 +1426,16 @@
stat = chip->ecc.correct(mtd, p,
&chip->buffers->ecccode[i], &chip->buffers->ecccalc[i]);
+ if (stat == -EBADMSG &&
+ (chip->ecc.options & NAND_ECC_GENERIC_ERASED_CHECK)) {
+ /* check for empty pages with bitflips */
+ stat = nand_check_erased_ecc_chunk(p, chip->ecc.size,
+ &chip->buffers->ecccode[i],
+ chip->ecc.bytes,
+ NULL, 0,
+ chip->ecc.strength);
+ }
+
if (stat < 0) {
mtd->ecc_stats.failed++;
} else {
@@ -1475,6 +1485,15 @@
int stat;
stat = chip->ecc.correct(mtd, p, &ecc_code[i], &ecc_calc[i]);
+ if (stat == -EBADMSG &&
+ (chip->ecc.options & NAND_ECC_GENERIC_ERASED_CHECK)) {
+ /* check for empty pages with bitflips */
+ stat = nand_check_erased_ecc_chunk(p, eccsize,
+ &ecc_code[i], eccbytes,
+ NULL, 0,
+ chip->ecc.strength);
+ }
+
if (stat < 0) {
mtd->ecc_stats.failed++;
} else {
@@ -1527,6 +1546,15 @@
chip->ecc.calculate(mtd, p, &ecc_calc[i]);
stat = chip->ecc.correct(mtd, p, &ecc_code[i], NULL);
+ if (stat == -EBADMSG &&
+ (chip->ecc.options & NAND_ECC_GENERIC_ERASED_CHECK)) {
+ /* check for empty pages with bitflips */
+ stat = nand_check_erased_ecc_chunk(p, eccsize,
+ &ecc_code[i], eccbytes,
+ NULL, 0,
+ chip->ecc.strength);
+ }
+
if (stat < 0) {
mtd->ecc_stats.failed++;
} else {
@@ -1554,6 +1582,7 @@
int i, eccsize = chip->ecc.size;
int eccbytes = chip->ecc.bytes;
int eccsteps = chip->ecc.steps;
+ int eccpadbytes = eccbytes + chip->ecc.prepad + chip->ecc.postpad;
uint8_t *p = buf;
uint8_t *oob = chip->oob_poi;
unsigned int max_bitflips = 0;
@@ -1573,19 +1602,29 @@
chip->read_buf(mtd, oob, eccbytes);
stat = chip->ecc.correct(mtd, p, oob, NULL);
- if (stat < 0) {
- mtd->ecc_stats.failed++;
- } else {
- mtd->ecc_stats.corrected += stat;
- max_bitflips = max_t(unsigned int, max_bitflips, stat);
- }
-
oob += eccbytes;
if (chip->ecc.postpad) {
chip->read_buf(mtd, oob, chip->ecc.postpad);
oob += chip->ecc.postpad;
}
+
+ if (stat == -EBADMSG &&
+ (chip->ecc.options & NAND_ECC_GENERIC_ERASED_CHECK)) {
+ /* check for empty pages with bitflips */
+ stat = nand_check_erased_ecc_chunk(p, chip->ecc.size,
+ oob - eccpadbytes,
+ eccpadbytes,
+ NULL, 0,
+ chip->ecc.strength);
+ }
+
+ if (stat < 0) {
+ mtd->ecc_stats.failed++;
+ } else {
+ mtd->ecc_stats.corrected += stat;
+ max_bitflips = max_t(unsigned int, max_bitflips, stat);
+ }
}
/* Calculate remaining oob bytes */