mtd: nand: pxa3xx: re-read a page in raw mode on uncorrectable error

[platform/kernel/u-boot.git] / drivers / mtd / nand / raw / pxa3xx_nand.c

diff --git a/drivers/mtd/nand/raw/pxa3xx_nand.c b/drivers/mtd/nand/raw/pxa3xx_nand.c
index 4545973..492485b 100644 (file)
--- a/drivers/mtd/nand/raw/pxa3xx_nand.c
+++ b/drivers/mtd/nand/raw/pxa3xx_nand.c
@@ -1237,6 +1237,7 @@ static int pxa3xx_nand_read_page_hwecc(struct mtd_info *mtd,
 {
        struct pxa3xx_nand_host *host = nand_get_controller_data(chip);
        struct pxa3xx_nand_info *info = host->info_data;
+       int bf;
 
        chip->read_buf(mtd, buf, mtd->writesize);
        chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
@@ -1244,12 +1245,30 @@ static int pxa3xx_nand_read_page_hwecc(struct mtd_info *mtd,
        if (info->retcode == ERR_CORERR && info->use_ecc) {
                mtd->ecc_stats.corrected += info->ecc_err_cnt;
 
-       } else if (info->retcode == ERR_UNCORERR) {
+       } else if (info->retcode == ERR_UNCORERR && info->ecc_bch) {
                /*
-                * for blank page (all 0xff), HW will calculate its ECC as
-                * 0, which is different from the ECC information within
-                * OOB, ignore such uncorrectable errors
+                * Empty pages will trigger uncorrectable errors. Re-read the
+                * entire page in raw mode and check for bits not being "1".
+                * If there are more than the supported strength, then it means
+                * this is an actual uncorrectable error.
                 */
+               chip->ecc.read_page_raw(mtd, chip, buf, oob_required, page);
+               bf = nand_check_erased_ecc_chunk(buf, mtd->writesize,
+                                                chip->oob_poi, mtd->oobsize,
+                                                NULL, 0, chip->ecc.strength);
+               if (bf < 0) {
+                       mtd->ecc_stats.failed++;
+               } else if (bf) {
+                       mtd->ecc_stats.corrected += bf;
+                       info->max_bitflips = max_t(unsigned int,
+                                                  info->max_bitflips, bf);
+                       info->retcode = ERR_CORERR;
+               } else {
+                       info->retcode = ERR_NONE;
+               }
+
+       } else if (info->retcode == ERR_UNCORERR && !info->ecc_bch) {
+               /* Raw read is not supported with Hamming ECC engine */
                if (is_buf_blank(buf, mtd->writesize))
                        info->retcode = ERR_NONE;
                else