[PATCH v4 1/5] mtd: nand: return consistent error codes in ecc.correct() implementations
Boris Brezillon
boris.brezillon at free-electrons.com
Wed Dec 30 11:32:03 PST 2015
The error code returned by the ecc.correct() are not consistent over the
all implementations.
Document the expected behavior in include/linux/mtd/nand.h and fix
offending implementations.
Signed-off-by: Boris Brezillon <boris.brezillon at free-electrons.com>
---
drivers/mtd/nand/atmel_nand.c | 2 +-
drivers/mtd/nand/bf5xx_nand.c | 20 ++++++++++++++------
drivers/mtd/nand/davinci_nand.c | 6 +++---
drivers/mtd/nand/jz4740_nand.c | 4 ++--
drivers/mtd/nand/mxc_nand.c | 4 ++--
drivers/mtd/nand/nand_bch.c | 2 +-
drivers/mtd/nand/nand_ecc.c | 2 +-
drivers/mtd/nand/omap2.c | 6 +++---
drivers/mtd/nand/r852.c | 4 ++--
include/linux/mtd/nand.h | 8 +++++++-
include/linux/mtd/nand_bch.h | 2 +-
11 files changed, 37 insertions(+), 23 deletions(-)
diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c
index 18c4e14..b216bf5 100644
--- a/drivers/mtd/nand/atmel_nand.c
+++ b/drivers/mtd/nand/atmel_nand.c
@@ -1445,7 +1445,7 @@ static int atmel_nand_correct(struct mtd_info *mtd, u_char *dat,
* We can't correct so many errors */
dev_dbg(host->dev, "atmel_nand : multiple errors detected."
" Unable to correct.\n");
- return -EIO;
+ return -EBADMSG;
}
/* if there's a single bit error : we can correct it */
diff --git a/drivers/mtd/nand/bf5xx_nand.c b/drivers/mtd/nand/bf5xx_nand.c
index 9514e13..89d9414 100644
--- a/drivers/mtd/nand/bf5xx_nand.c
+++ b/drivers/mtd/nand/bf5xx_nand.c
@@ -252,7 +252,7 @@ static int bf5xx_nand_correct_data_256(struct mtd_info *mtd, u_char *dat,
*/
if (hweight32(syndrome[0]) == 1) {
dev_err(info->device, "ECC data was incorrect!\n");
- return 1;
+ return -EBADMSG;
}
syndrome[1] = (calced & 0x7FF) ^ (stored & 0x7FF);
@@ -285,7 +285,7 @@ static int bf5xx_nand_correct_data_256(struct mtd_info *mtd, u_char *dat,
data = data ^ (0x1 << failing_bit);
*(dat + failing_byte) = data;
- return 0;
+ return 1;
}
/*
@@ -298,26 +298,34 @@ static int bf5xx_nand_correct_data_256(struct mtd_info *mtd, u_char *dat,
dev_err(info->device,
"Please discard data, mark bad block\n");
- return 1;
+ return -EBADMSG;
}
static int bf5xx_nand_correct_data(struct mtd_info *mtd, u_char *dat,
u_char *read_ecc, u_char *calc_ecc)
{
struct nand_chip *chip = mtd_to_nand(mtd);
- int ret;
+ int ret, bitflips = 0;
ret = bf5xx_nand_correct_data_256(mtd, dat, read_ecc, calc_ecc);
+ if (ret < 0)
+ return ret;
+
+ bitflips = ret;
/* If ecc size is 512, correct second 256 bytes */
if (chip->ecc.size == 512) {
dat += 256;
read_ecc += 3;
calc_ecc += 3;
- ret |= bf5xx_nand_correct_data_256(mtd, dat, read_ecc, calc_ecc);
+ ret = bf5xx_nand_correct_data_256(mtd, dat, read_ecc, calc_ecc);
+ if (ret < 0)
+ return ret;
+
+ bitflips += ret;
}
- return ret;
+ return bitflips;
}
static void bf5xx_nand_enable_hwecc(struct mtd_info *mtd, int mode)
diff --git a/drivers/mtd/nand/davinci_nand.c b/drivers/mtd/nand/davinci_nand.c
index 3b49fe8..ddb73c3 100644
--- a/drivers/mtd/nand/davinci_nand.c
+++ b/drivers/mtd/nand/davinci_nand.c
@@ -207,7 +207,7 @@ static int nand_davinci_correct_1bit(struct mtd_info *mtd, u_char *dat,
dat[diff >> (12 + 3)] ^= BIT((diff >> 12) & 7);
return 1;
} else {
- return -1;
+ return -EBADMSG;
}
} else if (!(diff & (diff - 1))) {
/* Single bit ECC error in the ECC itself,
@@ -215,7 +215,7 @@ static int nand_davinci_correct_1bit(struct mtd_info *mtd, u_char *dat,
return 1;
} else {
/* Uncorrectable error */
- return -1;
+ return -EBADMSG;
}
}
@@ -391,7 +391,7 @@ compare:
return 0;
case 1: /* five or more errors detected */
davinci_nand_readl(info, NAND_ERR_ERRVAL1_OFFSET);
- return -EIO;
+ return -EBADMSG;
case 2: /* error addresses computed */
case 3:
num_errors = 1 + ((fsr >> 16) & 0x03);
diff --git a/drivers/mtd/nand/jz4740_nand.c b/drivers/mtd/nand/jz4740_nand.c
index a2363d3..adccae3 100644
--- a/drivers/mtd/nand/jz4740_nand.c
+++ b/drivers/mtd/nand/jz4740_nand.c
@@ -254,7 +254,7 @@ static int jz_nand_correct_ecc_rs(struct mtd_info *mtd, uint8_t *dat,
} while (!(status & JZ_NAND_STATUS_DEC_FINISH) && --timeout);
if (timeout == 0)
- return -1;
+ return -ETIMEDOUT;
reg = readl(nand->base + JZ_REG_NAND_ECC_CTRL);
reg &= ~JZ_NAND_ECC_CTRL_ENABLE;
@@ -262,7 +262,7 @@ static int jz_nand_correct_ecc_rs(struct mtd_info *mtd, uint8_t *dat,
if (status & JZ_NAND_STATUS_ERROR) {
if (status & JZ_NAND_STATUS_UNCOR_ERROR)
- return -1;
+ return -EBADMSG;
error_count = (status & JZ_NAND_STATUS_ERR_COUNT) >> 29;
diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c
index 9540099..66e56bb 100644
--- a/drivers/mtd/nand/mxc_nand.c
+++ b/drivers/mtd/nand/mxc_nand.c
@@ -674,7 +674,7 @@ static int mxc_nand_correct_data_v1(struct mtd_info *mtd, u_char *dat,
if (((ecc_status & 0x3) == 2) || ((ecc_status >> 2) == 2)) {
pr_debug("MXC_NAND: HWECC uncorrectable 2-bit ECC error\n");
- return -1;
+ return -EBADMSG;
}
return 0;
@@ -701,7 +701,7 @@ static int mxc_nand_correct_data_v2_v3(struct mtd_info *mtd, u_char *dat,
err = ecc_stat & ecc_bit_mask;
if (err > err_limit) {
printk(KERN_WARNING "UnCorrectable RS-ECC Error\n");
- return -1;
+ return -EBADMSG;
} else {
ret += err;
}
diff --git a/drivers/mtd/nand/nand_bch.c b/drivers/mtd/nand/nand_bch.c
index e5758d8..a87c1b6 100644
--- a/drivers/mtd/nand/nand_bch.c
+++ b/drivers/mtd/nand/nand_bch.c
@@ -98,7 +98,7 @@ int nand_bch_correct_data(struct mtd_info *mtd, unsigned char *buf,
}
} else if (count < 0) {
printk(KERN_ERR "ecc unrecoverable error\n");
- count = -1;
+ count = -EBADMSG;
}
return count;
}
diff --git a/drivers/mtd/nand/nand_ecc.c b/drivers/mtd/nand/nand_ecc.c
index e612985..d1770b0 100644
--- a/drivers/mtd/nand/nand_ecc.c
+++ b/drivers/mtd/nand/nand_ecc.c
@@ -507,7 +507,7 @@ int __nand_correct_data(unsigned char *buf,
return 1; /* error in ECC data; no action needed */
pr_err("%s: uncorrectable ECC error\n", __func__);
- return -1;
+ return -EBADMSG;
}
EXPORT_SYMBOL(__nand_correct_data);
diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
index e9cbbc6..c553f78 100644
--- a/drivers/mtd/nand/omap2.c
+++ b/drivers/mtd/nand/omap2.c
@@ -826,12 +826,12 @@ static int omap_compare_ecc(u8 *ecc_data1, /* read from NAND memory */
case 1:
/* Uncorrectable error */
pr_debug("ECC UNCORRECTED_ERROR 1\n");
- return -1;
+ return -EBADMSG;
case 11:
/* UN-Correctable error */
pr_debug("ECC UNCORRECTED_ERROR B\n");
- return -1;
+ return -EBADMSG;
case 12:
/* Correctable error */
@@ -861,7 +861,7 @@ static int omap_compare_ecc(u8 *ecc_data1, /* read from NAND memory */
return 0;
}
pr_debug("UNCORRECTED_ERROR default\n");
- return -1;
+ return -EBADMSG;
}
}
diff --git a/drivers/mtd/nand/r852.c b/drivers/mtd/nand/r852.c
index cb0bf09..5b15f2f 100644
--- a/drivers/mtd/nand/r852.c
+++ b/drivers/mtd/nand/r852.c
@@ -477,7 +477,7 @@ static int r852_ecc_correct(struct mtd_info *mtd, uint8_t *dat,
if (dev->dma_error) {
dev->dma_error = 0;
- return -1;
+ return -EIO;
}
r852_write_reg(dev, R852_CTL, dev->ctlreg | R852_CTL_ECC_ACCESS);
@@ -491,7 +491,7 @@ static int r852_ecc_correct(struct mtd_info *mtd, uint8_t *dat,
/* ecc uncorrectable error */
if (ecc_status & R852_ECC_FAIL) {
dbg("ecc: unrecoverable error, in half %d", i);
- error = -1;
+ error = -EBADMSG;
goto exit;
}
diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index 3e92be1..5189581 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -456,7 +456,13 @@ struct nand_hw_control {
* @hwctl: function to control hardware ECC generator. Must only
* be provided if an hardware ECC is available
* @calculate: function for ECC calculation or readback from ECC hardware
- * @correct: function for ECC correction, matching to ECC generator (sw/hw)
+ * @correct: function for ECC correction, matching to ECC generator (sw/hw).
+ * Should return a positive number representing the number of
+ * corrected bitflips, -EBADMSG if the number of bitflips exceed
+ * ECC strength, or any other error code if the error is not
+ * directly related to correction.
+ * If -EBADMSG is returned the input buffers should be left
+ * untouched.
* @read_page_raw: function to read a raw page without ECC. This function
* should hide the specific layout used by the ECC
* controller and always return contiguous in-band and
diff --git a/include/linux/mtd/nand_bch.h b/include/linux/mtd/nand_bch.h
index 74acf53..fb0bc34 100644
--- a/include/linux/mtd/nand_bch.h
+++ b/include/linux/mtd/nand_bch.h
@@ -55,7 +55,7 @@ static inline int
nand_bch_correct_data(struct mtd_info *mtd, unsigned char *buf,
unsigned char *read_ecc, unsigned char *calc_ecc)
{
- return -1;
+ return -ENOTSUPP;
}
static inline struct nand_bch_control *
--
2.1.4
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