}
/*
+ * Bitflips can happen in erased codewords also so this function counts the
+ * number of 0 in each CW for which ECC engine returns the uncorrectable
+ * error. The page will be assumed as erased if this count is less than or
+ * equal to the ecc->strength for each CW.
+ *
+ * 1. Both DATA and OOB need to be checked for number of 0. The
+ * top-level API can be called with only data buf or OOB buf so use
+ * chip->data_buf if data buf is null and chip->oob_poi if oob buf
+ * is null for copying the raw bytes.
+ * 2. Perform raw read for all the CW which has uncorrectable errors.
+ * 3. For each CW, check the number of 0 in cw_data and usable OOB bytes.
+ * The BBM and spare bytes bit flip won’t affect the ECC so don’t check
+ * the number of bitflips in this area.
+ */
+static int
+check_for_erased_page(struct qcom_nand_host *host, u8 *data_buf,
+ u8 *oob_buf, unsigned long uncorrectable_cws,
+ int page, unsigned int max_bitflips)
+{
+ struct nand_chip *chip = &host->chip;
+ struct mtd_info *mtd = nand_to_mtd(chip);
+ struct nand_ecc_ctrl *ecc = &chip->ecc;
+ u8 *cw_data_buf, *cw_oob_buf;
+ int cw, data_size, oob_size, ret = 0;
+
+ if (!data_buf) {
+ data_buf = chip->data_buf;
+ chip->pagebuf = -1;
+ }
+
+ if (!oob_buf) {
+ oob_buf = chip->oob_poi;
+ chip->pagebuf = -1;
+ }
+
+ for_each_set_bit(cw, &uncorrectable_cws, ecc->steps) {
+ if (cw == (ecc->steps - 1)) {
+ data_size = ecc->size - ((ecc->steps - 1) * 4);
+ oob_size = (ecc->steps * 4) + host->ecc_bytes_hw;
+ } else {
+ data_size = host->cw_data;
+ oob_size = host->ecc_bytes_hw;
+ }
+
+ /* determine starting buffer address for current CW */
+ cw_data_buf = data_buf + (cw * host->cw_data);
+ cw_oob_buf = oob_buf + (cw * ecc->bytes);
+
+ ret = qcom_nandc_read_cw_raw(mtd, chip, cw_data_buf,
+ cw_oob_buf, page, cw);
+ if (ret)
+ return ret;
+
+ /*
+ * make sure it isn't an erased page reported
+ * as not-erased by HW because of a few bitflips
+ */
+ ret = nand_check_erased_ecc_chunk(cw_data_buf, data_size,
+ cw_oob_buf + host->bbm_size,
+ oob_size, NULL,
+ 0, ecc->strength);
+ if (ret < 0) {
+ mtd->ecc_stats.failed++;
+ } else {
+ mtd->ecc_stats.corrected += ret;
+ max_bitflips = max_t(unsigned int, max_bitflips, ret);
+ }
+ }
+
+ return max_bitflips;
+}
+
+/*
* reads back status registers set by the controller to notify page read
* errors. this is equivalent to what 'ecc->correct()' would do.
*/
static int parse_read_errors(struct qcom_nand_host *host, u8 *data_buf,
- u8 *oob_buf)
+ u8 *oob_buf, int page)
{
struct nand_chip *chip = &host->chip;
struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
struct mtd_info *mtd = nand_to_mtd(chip);
struct nand_ecc_ctrl *ecc = &chip->ecc;
- unsigned int max_bitflips = 0;
+ unsigned int max_bitflips = 0, uncorrectable_cws = 0;
struct read_stats *buf;
- bool flash_op_err = false;
+ bool flash_op_err = false, erased;
int i;
+ u8 *data_buf_start = data_buf, *oob_buf_start = oob_buf;
buf = (struct read_stats *)nandc->reg_read_buf;
nandc_read_buffer_sync(nandc, true);
* codeword detection check will be done.
*/
if ((flash & FS_OP_ERR) && (buffer & BS_UNCORRECTABLE_BIT)) {
- bool erased;
- int ret, ecclen, extraooblen;
- void *eccbuf;
-
/*
* For BCH ECC, ignore erased codeword errors, if
* ERASED_CW bits are set.
erased = false;
}
- if (erased) {
- data_buf += data_len;
- if (oob_buf)
- oob_buf += oob_len + ecc->bytes;
- continue;
- }
-
- eccbuf = oob_buf ? oob_buf + oob_len : NULL;
- ecclen = oob_buf ? host->ecc_bytes_hw : 0;
- extraooblen = oob_buf ? oob_len : 0;
-
- /*
- * make sure it isn't an erased page reported
- * as not-erased by HW because of a few bitflips
- */
- ret = nand_check_erased_ecc_chunk(data_buf,
- data_len, eccbuf, ecclen, oob_buf,
- extraooblen, ecc->strength);
- if (ret < 0) {
- mtd->ecc_stats.failed++;
- } else {
- mtd->ecc_stats.corrected += ret;
- max_bitflips =
- max_t(unsigned int, max_bitflips, ret);
- }
+ if (!erased)
+ uncorrectable_cws |= BIT(i);
/*
* Check if MPU or any other operational error (timeout,
* device failure, etc.) happened for this codeword and
if (flash_op_err)
return -EIO;
- return max_bitflips;
+ if (!uncorrectable_cws)
+ return max_bitflips;
+
+ return check_for_erased_page(host, data_buf_start, oob_buf_start,
+ uncorrectable_cws, page,
+ max_bitflips);
}
/*
* ecc->read_oob()
*/
static int read_page_ecc(struct qcom_nand_host *host, u8 *data_buf,
- u8 *oob_buf)
+ u8 *oob_buf, int page)
{
struct nand_chip *chip = &host->chip;
struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
return ret;
}
- return parse_read_errors(host, data_buf_start, oob_buf_start);
+ return parse_read_errors(host, data_buf_start, oob_buf_start, page);
}
/*
clear_bam_transaction(nandc);
- return read_page_ecc(host, data_buf, oob_buf);
+ return read_page_ecc(host, data_buf, oob_buf, page);
}
/* implements ecc->read_page_raw() */
set_address(host, 0, page);
update_rw_regs(host, ecc->steps, true);
- return read_page_ecc(host, NULL, chip->oob_poi);
+ return read_page_ecc(host, NULL, chip->oob_poi, page);
}
/* implements ecc->write_page() */