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-rw-r--r--drivers/mtd/nand/nand_base.c53
-rw-r--r--include/linux/mtd/nand.h10
2 files changed, 56 insertions, 7 deletions
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 50514f2501bb..f2c8ff398d6c 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -1426,6 +1426,16 @@ static int nand_read_subpage(struct mtd_info *mtd, struct nand_chip *chip,
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 @@ static int nand_read_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
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 @@ static int nand_read_page_hwecc_oob_first(struct mtd_info *mtd,
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 @@ static int nand_read_page_syndrome(struct mtd_info *mtd, struct nand_chip *chip,
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 @@ static int nand_read_page_syndrome(struct mtd_info *mtd, struct nand_chip *chip,
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 */
diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index 518958115182..86487dbe7358 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -129,6 +129,14 @@ typedef enum {
/* Enable Hardware ECC before syndrome is read back from flash */
#define NAND_ECC_READSYN 2
+/*
+ * Enable generic NAND 'page erased' check. This check is only done when
+ * ecc.correct() returns -EBADMSG.
+ * Set this flag if your implementation does not fix bitflips in erased
+ * pages and you want to rely on the default implementation.
+ */
+#define NAND_ECC_GENERIC_ERASED_CHECK BIT(0)
+
/* Bit mask for flags passed to do_nand_read_ecc */
#define NAND_GET_DEVICE 0x80
@@ -451,6 +459,7 @@ struct nand_hw_control {
* @total: total number of ECC bytes per page
* @prepad: padding information for syndrome based ECC generators
* @postpad: padding information for syndrome based ECC generators
+ * @options: ECC specific options (see NAND_ECC_XXX flags defined above)
* @layout: ECC layout control struct pointer
* @priv: pointer to private ECC control data
* @hwctl: function to control hardware ECC generator. Must only
@@ -500,6 +509,7 @@ struct nand_ecc_ctrl {
int strength;
int prepad;
int postpad;
+ unsigned int options;
struct nand_ecclayout *layout;
void *priv;
void (*hwctl)(struct mtd_info *mtd, int mode);