From f5bbdacc41939f89d8ccb18dd79cd9b21c0cb75d Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 25 May 2006 10:07:16 +0200 Subject: [MTD] NAND Modularize read function Split the core of the read function out and implement seperate handling functions for software and hardware ECC. Signed-off-by: Thomas Gleixner --- drivers/mtd/nand/diskonchip.c | 4 +- drivers/mtd/nand/nand_base.c | 448 +++++++++++++++++++++--------------------- drivers/mtd/nand/rtc_from4.c | 62 +++--- 3 files changed, 267 insertions(+), 247 deletions(-) (limited to 'drivers') diff --git a/drivers/mtd/nand/diskonchip.c b/drivers/mtd/nand/diskonchip.c index 2ec9080e2b14..83af6f05cd00 100644 --- a/drivers/mtd/nand/diskonchip.c +++ b/drivers/mtd/nand/diskonchip.c @@ -968,12 +968,14 @@ static int doc200x_calculate_ecc(struct mtd_info *mtd, const u_char *dat, unsign return 0; } -static int doc200x_correct_data(struct mtd_info *mtd, u_char *dat, u_char *read_ecc, u_char *calc_ecc) +static int doc200x_correct_data(struct mtd_info *mtd, u_char *dat, + u_char *read_ecc, u_char *isnull) { int i, ret = 0; struct nand_chip *this = mtd->priv; struct doc_priv *doc = this->priv; void __iomem *docptr = doc->virtadr; + uint8_t calc_ecc[6]; volatile u_char dummy; int emptymatch = 1; diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c index 49bca242610b..21fce2bce4b2 100644 --- a/drivers/mtd/nand/nand_base.c +++ b/drivers/mtd/nand/nand_base.c @@ -976,256 +976,224 @@ static int nand_verify_pages(struct mtd_info *mtd, struct nand_chip *chip, int p #endif /** - * nand_read - [MTD Interface] MTD compability function for nand_do_read_ecc - * @mtd: MTD device structure - * @from: offset to read from - * @len: number of bytes to read - * @retlen: pointer to variable to store the number of read bytes - * @buf: the databuffer to put data - * - * This function simply calls nand_do_read_ecc with oob buffer and oobsel = NULL - * and flags = 0xff + * nand_read_page_swecc - {REPLACABLE] software ecc based page read function + * @mtd: mtd info structure + * @chip: nand chip info structure + * @buf: buffer to store read data */ -static int nand_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, uint8_t *buf) +static int nand_read_page_swecc(struct mtd_info *mtd, struct nand_chip *chip, + uint8_t *buf) { - return nand_do_read_ecc(mtd, from, len, retlen, buf, NULL, &mtd->oobinfo, 0xff); + int i, eccsize = chip->ecc.size; + int eccbytes = chip->ecc.bytes; + int eccsteps = chip->ecc.steps; + uint8_t *p = buf; + uint8_t *ecc_calc = chip->oob_buf + mtd->oobsize; + uint8_t *ecc_code = ecc_calc + mtd->oobsize; + int *eccpos = chip->autooob->eccpos; + + chip->read_buf(mtd, buf, mtd->writesize); + chip->read_buf(mtd, chip->oob_buf, mtd->oobsize); + + if (chip->ecc.mode == NAND_ECC_NONE) + return 0; + + for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) + chip->ecc.calculate(mtd, p, &ecc_calc[i]); + + for (i = 0; i < chip->ecc.total; i++) + ecc_code[i] = chip->oob_buf[eccpos[i]]; + + eccsteps = chip->ecc.steps; + p = buf; + + for (i = 0 ; eccsteps; eccsteps--, i += eccbytes, p += eccsize) { + int stat; + + stat = chip->ecc.correct(mtd, p, &ecc_code[i], &ecc_calc[i]); + if (stat == -1) + mtd->ecc_stats.failed++; + else + mtd->ecc_stats.corrected += stat; + } + return 0; } /** - * nand_do_read_ecc - [MTD Interface] Read data with ECC - * @mtd: MTD device structure - * @from: offset to read from - * @len: number of bytes to read - * @retlen: pointer to variable to store the number of read bytes - * @buf: the databuffer to put data - * @oob_buf: filesystem supplied oob data buffer (can be NULL) - * @oobsel: oob selection structure - * @flags: flag to indicate if nand_get_device/nand_release_device should be preformed - * and how many corrected error bits are acceptable: - * bits 0..7 - number of tolerable errors - * bit 8 - 0 == do not get/release chip, 1 == get/release chip + * nand_read_page_hwecc - {REPLACABLE] hardware ecc based page read function + * @mtd: mtd info structure + * @chip: nand chip info structure + * @buf: buffer to store read data * - * NAND read with ECC + * Not for syndrome calculating ecc controllers which need a special oob layout */ -int nand_do_read_ecc(struct mtd_info *mtd, loff_t from, size_t len, - size_t *retlen, uint8_t *buf, uint8_t *oob_buf, struct nand_oobinfo *oobsel, int flags) +static int nand_read_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip, + uint8_t *buf) { - - int i, j, col, realpage, page, end, ecc, chipnr, sndcmd = 1; - int read = 0, oob = 0, ecc_status = 0, ecc_failed = 0; - struct nand_chip *chip = mtd->priv; - uint8_t *data_poi, *oob_data = oob_buf; - uint8_t ecc_calc[32]; - uint8_t ecc_code[32]; - int eccmode, eccsteps; - int *oob_config, datidx; - int blockcheck = (1 << (chip->phys_erase_shift - chip->page_shift)) - 1; - int eccbytes; - int compareecc = 1; - int oobreadlen; - - DEBUG(MTD_DEBUG_LEVEL3, "nand_read_ecc: from = 0x%08x, len = %i\n", (unsigned int)from, (int)len); - - /* Do not allow reads past end of device */ - if ((from + len) > mtd->size) { - DEBUG(MTD_DEBUG_LEVEL0, "nand_read_ecc: Attempt read beyond end of device\n"); - *retlen = 0; - return -EINVAL; + int i, eccsize = chip->ecc.size; + int eccbytes = chip->ecc.bytes; + int eccsteps = chip->ecc.steps; + uint8_t *p = buf; + uint8_t *ecc_calc = chip->oob_buf + mtd->oobsize; + uint8_t *ecc_code = ecc_calc + mtd->oobsize; + int *eccpos = chip->autooob->eccpos; + + for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) { + chip->ecc.hwctl(mtd, NAND_ECC_READ); + chip->read_buf(mtd, p, eccsize); + chip->ecc.calculate(mtd, p, &ecc_calc[i]); } + chip->read_buf(mtd, chip->oob_buf, mtd->oobsize); - /* Grab the lock and see if the device is available */ - if (flags & NAND_GET_DEVICE) - nand_get_device(chip, mtd, FL_READING); + for (i = 0; i < chip->ecc.total; i++) + ecc_code[i] = chip->oob_buf[eccpos[i]]; - /* Autoplace of oob data ? Use the default placement scheme */ - if (oobsel->useecc == MTD_NANDECC_AUTOPLACE) - oobsel = chip->autooob; + eccsteps = chip->ecc.steps; + p = buf; - eccmode = oobsel->useecc ? chip->ecc.mode : NAND_ECC_NONE; - oob_config = oobsel->eccpos; + for (i = 0 ; eccsteps; eccsteps--, i += eccbytes, p += eccsize) { + int stat; - /* Select the NAND device */ - chipnr = (int)(from >> chip->chip_shift); - chip->select_chip(mtd, chipnr); - - /* First we calculate the starting page */ - realpage = (int)(from >> chip->page_shift); - page = realpage & chip->pagemask; + stat = chip->ecc.correct(mtd, p, &ecc_code[i], &ecc_calc[i]); + if (stat == -1) + mtd->ecc_stats.failed++; + else + mtd->ecc_stats.corrected += stat; + } + return 0; +} - /* Get raw starting column */ - col = from & (mtd->writesize - 1); +/** + * nand_read_page_syndrome - {REPLACABLE] hardware ecc syndrom based page read + * @mtd: mtd info structure + * @chip: nand chip info structure + * @buf: buffer to store read data + * + * The hw generator calculates the error syndrome automatically. Therefor + * we need a special oob layout and . + */ +static int nand_read_page_syndrome(struct mtd_info *mtd, struct nand_chip *chip, + uint8_t *buf) +{ + int i, eccsize = chip->ecc.size; + int eccbytes = chip->ecc.bytes; + int eccsteps = chip->ecc.steps; + uint8_t *p = buf; + uint8_t *oob = chip->oob_buf; - end = mtd->writesize; - ecc = chip->ecc.size; - eccbytes = chip->ecc.bytes; + for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) { + int stat; - if ((eccmode == NAND_ECC_NONE) || (chip->options & NAND_HWECC_SYNDROME)) - compareecc = 0; + chip->ecc.hwctl(mtd, NAND_ECC_READ); + chip->read_buf(mtd, p, eccsize); - oobreadlen = mtd->oobsize; - if (chip->options & NAND_HWECC_SYNDROME) - oobreadlen -= oobsel->eccbytes; + if (chip->ecc.prepad) { + chip->read_buf(mtd, oob, chip->ecc.prepad); + oob += chip->ecc.prepad; + } - /* Loop until all data read */ - while (read < len) { + chip->ecc.hwctl(mtd, NAND_ECC_READSYN); + chip->read_buf(mtd, oob, eccbytes); + stat = chip->ecc.correct(mtd, p, oob, NULL); - int aligned = (!col && (len - read) >= end); - /* - * If the read is not page aligned, we have to read into data buffer - * due to ecc, else we read into return buffer direct - */ - if (aligned) - data_poi = &buf[read]; + if (stat == -1) + mtd->ecc_stats.failed++; else - data_poi = chip->data_buf; + mtd->ecc_stats.corrected += stat; - /* Check, if we have this page in the buffer - * - * FIXME: Make it work when we must provide oob data too, - * check the usage of data_buf oob field - */ - if (realpage == chip->pagebuf && !oob_buf) { - /* aligned read ? */ - if (aligned) - memcpy(data_poi, chip->data_buf, end); - goto readdata; - } + oob += eccbytes; - /* Check, if we must send the read command */ - if (sndcmd) { - chip->cmdfunc(mtd, NAND_CMD_READ0, 0x00, page); - sndcmd = 0; + if (chip->ecc.postpad) { + chip->read_buf(mtd, oob, chip->ecc.postpad); + oob += chip->ecc.postpad; } + } - /* get oob area, if we have no oob buffer from fs-driver */ - if (!oob_buf || oobsel->useecc == MTD_NANDECC_AUTOPLACE || - oobsel->useecc == MTD_NANDECC_AUTOPL_USR) - oob_data = &chip->data_buf[end]; - - eccsteps = chip->ecc.steps; - - switch (eccmode) { - case NAND_ECC_NONE:{ - /* No ECC, Read in a page */ - static unsigned long lastwhinge = 0; - if ((lastwhinge / HZ) != (jiffies / HZ)) { - printk(KERN_WARNING - "Reading data from NAND FLASH without ECC is not recommended\n"); - lastwhinge = jiffies; - } - chip->read_buf(mtd, data_poi, end); - break; - } + /* Calculate remaining oob bytes */ + i = oob - chip->oob_buf; + if (i) + chip->read_buf(mtd, oob, i); - case NAND_ECC_SOFT: /* Software ECC 3/256: Read in a page + oob data */ - chip->read_buf(mtd, data_poi, end); - for (i = 0, datidx = 0; eccsteps; eccsteps--, i += 3, datidx += ecc) - chip->ecc.calculate(mtd, &data_poi[datidx], &ecc_calc[i]); - break; + return 0; +} - default: - for (i = 0, datidx = 0; eccsteps; eccsteps--, i += eccbytes, datidx += ecc) { - chip->ecc.hwctl(mtd, NAND_ECC_READ); - chip->read_buf(mtd, &data_poi[datidx], ecc); - - /* HW ecc with syndrome calculation must read the - * syndrome from flash immidiately after the data */ - if (!compareecc) { - /* Some hw ecc generators need to know when the - * syndrome is read from flash */ - chip->ecc.hwctl(mtd, NAND_ECC_READSYN); - chip->read_buf(mtd, &oob_data[i], eccbytes); - /* We calc error correction directly, it checks the hw - * generator for an error, reads back the syndrome and - * does the error correction on the fly */ - ecc_status = chip->ecc.correct(mtd, &data_poi[datidx], &oob_data[i], &ecc_code[i]); - if ((ecc_status == -1) || (ecc_status > (flags && 0xff))) { - DEBUG(MTD_DEBUG_LEVEL0, "nand_read_ecc: " - "Failed ECC read, page 0x%08x on chip %d\n", page, chipnr); - ecc_failed++; - } - } else { - chip->ecc.calculate(mtd, &data_poi[datidx], &ecc_calc[i]); - } - } - break; - } +/** + * nand_do_read - [Internal] Read data with ECC + * + * @mtd: MTD device structure + * @from: offset to read from + * @len: number of bytes to read + * @retlen: pointer to variable to store the number of read bytes + * @buf: the databuffer to put data + * + * Internal function. Called with chip held. + */ +int nand_do_read(struct mtd_info *mtd, loff_t from, size_t len, + size_t *retlen, uint8_t *buf) +{ + int chipnr, page, realpage, col, bytes, aligned; + struct nand_chip *chip = mtd->priv; + struct mtd_ecc_stats stats; + int blkcheck = (1 << (chip->phys_erase_shift - chip->page_shift)) - 1; + int sndcmd = 1; + int ret = 0; + uint32_t readlen = len; + uint8_t *bufpoi; - /* read oobdata */ - chip->read_buf(mtd, &oob_data[mtd->oobsize - oobreadlen], oobreadlen); + stats = mtd->ecc_stats; - /* Skip ECC check, if not requested (ECC_NONE or HW_ECC with syndromes) */ - if (!compareecc) - goto readoob; + chipnr = (int)(from >> chip->chip_shift); + chip->select_chip(mtd, chipnr); - /* Pick the ECC bytes out of the oob data */ - for (j = 0; j < oobsel->eccbytes; j++) - ecc_code[j] = oob_data[oob_config[j]]; + realpage = (int)(from >> chip->page_shift); + page = realpage & chip->pagemask; - /* correct data, if necessary */ - for (i = 0, j = 0, datidx = 0; i < chip->ecc.steps; i++, datidx += ecc) { - ecc_status = chip->ecc.correct(mtd, &data_poi[datidx], &ecc_code[j], &ecc_calc[j]); + col = (int)(from & (mtd->writesize - 1)); - /* Get next chunk of ecc bytes */ - j += eccbytes; + while(1) { + bytes = min(mtd->writesize - col, readlen); + aligned = (bytes == mtd->writesize); - /* Check, if we have a fs supplied oob-buffer, - * This is the legacy mode. Used by YAFFS1 - * Should go away some day - */ - if (oob_buf && oobsel->useecc == MTD_NANDECC_PLACE) { - int *p = (int *)(&oob_data[mtd->oobsize]); - p[i] = ecc_status; - } + /* Is the current page in the buffer ? */ + if (realpage != chip->pagebuf) { + bufpoi = aligned ? buf : chip->data_buf; - if ((ecc_status == -1) || (ecc_status > (flags && 0xff))) { - DEBUG(MTD_DEBUG_LEVEL0, "nand_read_ecc: " "Failed ECC read, page 0x%08x\n", page); - ecc_failed++; + if (likely(sndcmd)) { + chip->cmdfunc(mtd, NAND_CMD_READ0, 0x00, page); + sndcmd = 0; } - } - readoob: - /* check, if we have a fs supplied oob-buffer */ - if (oob_buf) { - /* without autoplace. Legacy mode used by YAFFS1 */ - switch (oobsel->useecc) { - case MTD_NANDECC_AUTOPLACE: - case MTD_NANDECC_AUTOPL_USR: - /* Walk through the autoplace chunks */ - for (i = 0; oobsel->oobfree[i][1]; i++) { - int from = oobsel->oobfree[i][0]; - int num = oobsel->oobfree[i][1]; - memcpy(&oob_buf[oob], &oob_data[from], num); - oob += num; - } + /* Now read the page into the buffer */ + ret = chip->ecc.read_page(mtd, chip, bufpoi); + if (ret < 0) break; - case MTD_NANDECC_PLACE: - /* YAFFS1 legacy mode */ - oob_data += chip->ecc.steps * sizeof(int); - default: - oob_data += mtd->oobsize; + + /* Transfer not aligned data */ + if (!aligned) { + chip->pagebuf = realpage; + memcpy(buf, chip->data_buf + col, bytes); + } + + if (!(chip->options & NAND_NO_READRDY)) { + /* + * Apply delay or wait for ready/busy pin. Do + * this before the AUTOINCR check, so no + * problems arise if a chip which does auto + * increment is marked as NOAUTOINCR by the + * board driver. + */ + if (!chip->dev_ready) + udelay(chip->chip_delay); + else + nand_wait_ready(mtd); } - } - readdata: - /* Partial page read, transfer data into fs buffer */ - if (!aligned) { - for (j = col; j < end && read < len; j++) - buf[read++] = data_poi[j]; - chip->pagebuf = realpage; } else - read += mtd->writesize; + memcpy(buf, chip->data_buf + col, bytes); - /* Apply delay or wait for ready/busy pin - * Do this before the AUTOINCR check, so no problems - * arise if a chip which does auto increment - * is marked as NOAUTOINCR by the board driver. - */ - if (!chip->dev_ready) - udelay(chip->chip_delay); - else - nand_wait_ready(mtd); + buf += bytes; + readlen -= bytes; - if (read == len) + if (!readlen) break; /* For subsequent reads align to page boundary. */ @@ -1240,24 +1208,51 @@ int nand_do_read_ecc(struct mtd_info *mtd, loff_t from, size_t len, chip->select_chip(mtd, -1); chip->select_chip(mtd, chipnr); } + /* Check, if the chip supports auto page increment * or if we have hit a block boundary. */ - if (!NAND_CANAUTOINCR(chip) || !(page & blockcheck)) + if (!NAND_CANAUTOINCR(chip) || !(page & blkcheck)) sndcmd = 1; } - /* Deselect and wake up anyone waiting on the device */ - if (flags & NAND_GET_DEVICE) - nand_release_device(mtd); + *retlen = len - (size_t) readlen; - /* - * Return success, if no ECC failures, else -EBADMSG - * fs driver will take care of that, because - * retlen == desired len and result == -EBADMSG - */ - *retlen = read; - return ecc_failed ? -EBADMSG : 0; + if (ret) + return ret; + + return mtd->ecc_stats.failed - stats.failed ? -EBADMSG : 0; +} + +/** + * nand_read - [MTD Interface] MTD compability function for nand_do_read_ecc + * @mtd: MTD device structure + * @from: offset to read from + * @len: number of bytes to read + * @retlen: pointer to variable to store the number of read bytes + * @buf: the databuffer to put data + * + * Get hold of the chip and call nand_do_read + */ +static int nand_read(struct mtd_info *mtd, loff_t from, size_t len, + size_t *retlen, uint8_t *buf) +{ + int ret; + + *retlen = 0; + /* Do not allow reads past end of device */ + if ((from + len) > mtd->size) + return -EINVAL; + if (!len) + return 0; + + nand_get_device(mtd->priv, mtd, FL_READING); + + ret = nand_do_read(mtd, from, len, retlen, buf); + + nand_release_device(mtd); + + return ret; } /** @@ -2417,6 +2412,10 @@ int nand_scan(struct mtd_info *mtd, int maxchips) */ switch (chip->ecc.mode) { case NAND_ECC_HW: + /* Use standard hwecc read page function ? */ + if (!chip->ecc.read_page) + chip->ecc.read_page = nand_read_page_hwecc; + case NAND_ECC_HW_SYNDROME: if (!chip->ecc.calculate || !chip->ecc.correct || !chip->ecc.hwctl) { @@ -2424,6 +2423,10 @@ int nand_scan(struct mtd_info *mtd, int maxchips) "Hardware ECC not possible\n"); BUG(); } + /* Use standard syndrome read page function ? */ + if (!chip->ecc.read_page) + chip->ecc.read_page = nand_read_page_syndrome; + if (mtd->writesize >= chip->ecc.size) break; printk(KERN_WARNING "%d byte HW ECC not possible on " @@ -2434,6 +2437,7 @@ int nand_scan(struct mtd_info *mtd, int maxchips) case NAND_ECC_SOFT: chip->ecc.calculate = nand_calculate_ecc; chip->ecc.correct = nand_correct_data; + chip->ecc.read_page = nand_read_page_swecc; chip->ecc.size = 256; chip->ecc.bytes = 3; break; @@ -2441,6 +2445,7 @@ int nand_scan(struct mtd_info *mtd, int maxchips) case NAND_ECC_NONE: printk(KERN_WARNING "NAND_ECC_NONE selected by board driver. " "This is not recommended !!\n"); + chip->ecc.read_page = nand_read_page_swecc; chip->ecc.size = mtd->writesize; chip->ecc.bytes = 0; break; @@ -2459,6 +2464,7 @@ int nand_scan(struct mtd_info *mtd, int maxchips) printk(KERN_WARNING "Invalid ecc parameters\n"); BUG(); } + chip->ecc.total = chip->ecc.steps * chip->ecc.bytes; /* Initialize state */ chip->state = FL_READY; diff --git a/drivers/mtd/nand/rtc_from4.c b/drivers/mtd/nand/rtc_from4.c index 6c97bfaea19a..b7083104a05b 100644 --- a/drivers/mtd/nand/rtc_from4.c +++ b/drivers/mtd/nand/rtc_from4.c @@ -444,7 +444,8 @@ static int rtc_from4_correct_data(struct mtd_info *mtd, const u_char *buf, u_cha * note: see pages 34..37 of data sheet for details. * */ -static int rtc_from4_errstat(struct mtd_info *mtd, struct nand_chip *this, int state, int status, int page) +static int rtc_from4_errstat(struct mtd_info *mtd, struct nand_chip *this, + int state, int status, int page) { int er_stat = 0; int rtn, retlen; @@ -455,39 +456,50 @@ static int rtc_from4_errstat(struct mtd_info *mtd, struct nand_chip *this, int s this->cmdfunc(mtd, NAND_CMD_STATUS_CLEAR, -1, -1); if (state == FL_ERASING) { + for (i = 0; i < 4; i++) { - if (status & 1 << (i + 1)) { - this->cmdfunc(mtd, (NAND_CMD_STATUS_ERROR + i + 1), -1, -1); - rtn = this->read_byte(mtd); - this->cmdfunc(mtd, NAND_CMD_STATUS_RESET, -1, -1); - if (!(rtn & ERR_STAT_ECC_AVAILABLE)) { - er_stat |= 1 << (i + 1); /* err_ecc_not_avail */ - } - } + if (!(status & 1 << (i + 1))) + continue; + this->cmdfunc(mtd, (NAND_CMD_STATUS_ERROR + i + 1), + -1, -1); + rtn = this->read_byte(mtd); + this->cmdfunc(mtd, NAND_CMD_STATUS_RESET, -1, -1); + + /* err_ecc_not_avail */ + if (!(rtn & ERR_STAT_ECC_AVAILABLE)) + er_stat |= 1 << (i + 1); } + } else if (state == FL_WRITING) { + + unsigned long corrected = mtd->ecc_stats.corrected; + /* single bank write logic */ this->cmdfunc(mtd, NAND_CMD_STATUS_ERROR, -1, -1); rtn = this->read_byte(mtd); this->cmdfunc(mtd, NAND_CMD_STATUS_RESET, -1, -1); + if (!(rtn & ERR_STAT_ECC_AVAILABLE)) { - er_stat |= 1 << 1; /* err_ecc_not_avail */ - } else { - len = mtd->writesize; - buf = kmalloc(len, GFP_KERNEL); - if (!buf) { - printk(KERN_ERR "rtc_from4_errstat: Out of memory!\n"); - er_stat = 1; /* if we can't check, assume failed */ - } else { - /* recovery read */ - /* page read */ - rtn = nand_do_read_ecc(mtd, page, len, &retlen, buf, NULL, this->autooob, 1); - if (rtn) { /* if read failed or > 1-bit error corrected */ - er_stat |= 1 << 1; /* ECC read failed */ - } - kfree(buf); - } + /* err_ecc_not_avail */ + er_stat |= 1 << 1; + goto out; } + + len = mtd->writesize; + buf = kmalloc(len, GFP_KERNEL); + if (!buf) { + printk(KERN_ERR "rtc_from4_errstat: Out of memory!\n"); + er_stat = 1; + goto out; + } + + /* recovery read */ + rtn = nand_do_read(mtd, page, len, &retlen, buf); + + /* if read failed or > 1-bit error corrected */ + if (rtn || (mtd->ecc_stats.corrected - corrected) > 1) { + er_stat |= 1 << 1; + kfree(buf); } rtn = status; -- cgit v1.2.3