[PATCH 4/8] mtd: nand: mxc: Fix failed/corrected values for v2/v3 controllers

Sascha Hauer
2018-01-17T11:33:15Z

Currently nand_read_page_hwecc() from nand_base calls
mxc_nand_correct_data_v2_v3() for each subpage, but in this function we
return the corrected/failed results for the whole page instead
of a single subpage. On a 2k page size Nand this leads to results which
are 4 times too high.
The whole ecc.calculate/ecc.correct mechanism used by
nand_read_page_hwecc() is not suitable for devices which correct the
data in hardware, so fix this by using a driver specific read_page
function which does the right thing. Also add read_page_raw and read_oob
For proper raw and oob read support.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
drivers/mtd/nand/mxc_nand.c | 86 ++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 77 insertions(+), 9 deletions(-)

diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c
index ab9cd45237d3..48804320056f 100644
--- a/drivers/mtd/nand/mxc_nand.c
+++ b/drivers/mtd/nand/mxc_nand.c
@@ -140,6 +140,8 @@ struct mxc_nand_host;

struct mxc_nand_devtype_data {
void (*preset)(struct mtd_info *);
+ int (*read_page)(struct nand_chip *chip, void *buf, void *oob, bool ecc,
+ int page);
void (*send_cmd)(struct mxc_nand_host *, uint16_t, int);
void (*send_addr)(struct mxc_nand_host *, uint16_t, int);
void (*send_page)(struct mtd_info *, unsigned int);
@@ -757,13 +759,35 @@ static int mxc_nand_correct_data_v1(struct mtd_info *mtd, u_char *dat,
static int mxc_nand_correct_data_v2_v3(struct mtd_info *mtd, u_char *dat,
u_char *read_ecc, u_char *calc_ecc)
{
- struct nand_chip *nand_chip = mtd_to_nand(mtd);
- struct mxc_nand_host *host = nand_get_controller_data(nand_chip);
+ return 0;
+}
+
+static int mxc_nand_read_page_v2_v3(struct nand_chip *chip, void *buf,
+ void *oob, bool ecc, int page)
+{
+ struct mtd_info *mtd = nand_to_mtd(chip);
+ struct mxc_nand_host *host = nand_get_controller_data(chip);
+ unsigned int max_bitflips = 0;
u32 ecc_stat, err;
- int no_subpages = 1;
- int ret = 0;
+ int no_subpages;
u8 ecc_bit_mask, err_limit;

+ host->devtype_data->enable_hwecc(chip, ecc);
+
+ host->devtype_data->send_cmd(host, NAND_CMD_READ0, false);
+ mxc_do_addr_cycle(mtd, 0, page);
+
+ if (mtd->writesize > 512)
+ host->devtype_data->send_cmd(host,
+ NAND_CMD_READSTART, true);
+
+ host->devtype_data->send_page(mtd, NFC_OUTPUT);
+
+ if (buf)
+ memcpy32_fromio(buf, host->main_area0, mtd->writesize);
+ if (oob)
+ copy_spare(mtd, true, oob);
+
ecc_bit_mask = (host->eccsize == 4) ? 0x7 : 0xf;
err_limit = (host->eccsize == 4) ? 0x4 : 0x8;

@@ -774,17 +798,53 @@ static int mxc_nand_correct_data_v2_v3(struct mtd_info *mtd, u_char *dat,
do {
err = ecc_stat & ecc_bit_mask;
if (err > err_limit) {
- dev_dbg(host->dev, "UnCorrectable RS-ECC Error\n");
- return -EBADMSG;
+ mtd->ecc_stats.failed++;
} else {
- ret += err;
+ mtd->ecc_stats.corrected += err;
+ max_bitflips = max_t(unsigned int, max_bitflips, err);
}
+
ecc_stat >>= 4;
} while (--no_subpages);

- dev_dbg(host->dev, "%d Symbol Correctable RS-ECC Error\n", ret);
+ return max_bitflips;
+}

- return ret;
+static int mxc_nand_read_page(struct mtd_info *mtd, struct nand_chip *chip,
+ uint8_t *buf, int oob_required, int page)
+{
+ struct mxc_nand_host *host = nand_get_controller_data(chip);
+ void *oob_buf;
+
+ if (oob_required)
+ oob_buf = chip->oob_poi;
+ else
+ oob_buf = NULL;
+
+ return host->devtype_data->read_page(chip, buf, oob_buf, 1, page);
+}
+
+static int mxc_nand_read_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
+ uint8_t *buf, int oob_required, int page)
+{
+ struct mxc_nand_host *host = nand_get_controller_data(chip);
+ void *oob_buf;
+
+ if (oob_required)
+ oob_buf = chip->oob_poi;
+ else
+ oob_buf = NULL;
+
+ return host->devtype_data->read_page(chip, buf, oob_buf, 0, page);
+}
+
+static int mxc_nand_read_oob(struct mtd_info *mtd, struct nand_chip *chip,
+ int page)
+{
+ struct mxc_nand_host *host = nand_get_controller_data(chip);
+
+ return host->devtype_data->read_page(chip, NULL, chip->oob_poi, 0,
+ page);
}

static int mxc_nand_calculate_ecc(struct mtd_info *mtd, const u_char *dat,
@@ -1483,6 +1543,7 @@ static const struct mxc_nand_devtype_data imx27_nand_devtype_data = {
/* v21: i.MX25, i.MX35 */
static const struct mxc_nand_devtype_data imx25_nand_devtype_data = {
.preset = preset_v2,
+ .read_page = mxc_nand_read_page_v2_v3,
.send_cmd = send_cmd_v1_v2,
.send_addr = send_addr_v1_v2,
.send_page = send_page_v2,
@@ -1509,6 +1570,7 @@ static const struct mxc_nand_devtype_data imx25_nand_devtype_data = {
/* v3.2a: i.MX51 */
static const struct mxc_nand_devtype_data imx51_nand_devtype_data = {
.preset = preset_v3,
+ .read_page = mxc_nand_read_page_v2_v3,
.send_cmd = send_cmd_v3,
.send_addr = send_addr_v3,
.send_page = send_page_v3,
@@ -1535,6 +1597,7 @@ static const struct mxc_nand_devtype_data imx51_nand_devtype_data = {
/* v3.2b: i.MX53 */
static const struct mxc_nand_devtype_data imx53_nand_devtype_data = {
.preset = preset_v3,
+ .read_page = mxc_nand_read_page_v2_v3,
.send_cmd = send_cmd_v3,
.send_addr = send_addr_v3,
.send_page = send_page_v3,
@@ -1793,6 +1856,11 @@ static int mxcnd_probe(struct platform_device *pdev)

switch (this->ecc.mode) {
case NAND_ECC_HW:
+ if (host->devtype_data->read_page) {
+ this->ecc.read_page = mxc_nand_read_page;
+ this->ecc.read_page_raw = mxc_nand_read_page_raw;
+ this->ecc.read_oob = mxc_nand_read_oob;
+ }
this->ecc.calculate = mxc_nand_calculate_ecc;
this->ecc.hwctl = mxc_nand_enable_hwecc;
this->ecc.correct = host->devtype_data->correct_data;
--
2.11.0