[MTD] OneNAND: Single bit error detection

Idea from Jarkko Lavinen

Signed-off-by: Jarkko Lavinen <jarkko.lavinen@nokia.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>

diff --git a/drivers/mtd/onenand/onenand_base.c b/drivers/mtd/onenand/onenand_base.c
index bef4f26ad2edf8b6290f0a7cf4a3637537eaa57d..fc84ddc4987f82d40ea4d723d1d5f25c3bb92dbe 100644 (file)
--- a/drivers/mtd/onenand/onenand_base.c
+++ b/drivers/mtd/onenand/onenand_base.c
@@ -331,9 +331,12 @@ static int onenand_wait(struct mtd_info *mtd, int state)
 
        if (interrupt & ONENAND_INT_READ) {
                ecc = this->read_word(this->base + ONENAND_REG_ECC_STATUS);
-               if (ecc & ONENAND_ECC_2BIT_ALL) {
+               if (ecc) {
                        DEBUG(MTD_DEBUG_LEVEL0, "onenand_wait: ECC error = 0x%04x\n", ecc);
-                       return -EBADMSG;
+                       if (ecc & ONENAND_ECC_2BIT_ALL)
+                               mtd->ecc_stats.failed++;
+                       else if (ecc & ONENAND_ECC_1BIT_ALL)
+                               mtd->ecc_stats.corrected++;
                }
        }
 
@@ -715,6 +718,7 @@ static int onenand_read(struct mtd_info *mtd, loff_t from, size_t len,
        size_t *retlen, u_char *buf)
 {
        struct onenand_chip *this = mtd->priv;
+       struct mtd_ecc_stats stats;
        int read = 0, column;
        int thislen;
        int ret = 0;
@@ -733,6 +737,7 @@ static int onenand_read(struct mtd_info *mtd, loff_t from, size_t len,
 
        /* TODO handling oob */
 
+       stats = mtd->ecc_stats;
        while (read < len) {
                thislen = min_t(int, mtd->writesize, len - read);
 
@@ -774,7 +779,11 @@ out:
         * retlen == desired len and result == -EBADMSG
         */
        *retlen = read;
-       return ret;
+
+       if (mtd->ecc_stats.failed - stats.failed)
+               return -EBADMSG;
+
+       return mtd->ecc_stats.corrected - stats.corrected ? -EUCLEAN : 0;
 }
 
 /**
@@ -1390,7 +1399,6 @@ static int onenand_lock(struct mtd_info *mtd, loff_t ofs, size_t len)
        return onenand_do_lock_cmd(mtd, ofs, len, ONENAND_CMD_LOCK);
 }
 
-
 /**
  * onenand_unlock - [MTD Interface] Unlock block(s)
  * @param mtd          MTD device structure
@@ -1900,7 +1908,7 @@ static int onenand_probe(struct mtd_info *mtd)
        /* Read manufacturer and device IDs from Register */
        maf_id = this->read_word(this->base + ONENAND_REG_MANUFACTURER_ID);
        dev_id = this->read_word(this->base + ONENAND_REG_DEVICE_ID);
-       ver_id= this->read_word(this->base + ONENAND_REG_VERSION_ID);
+       ver_id = this->read_word(this->base + ONENAND_REG_VERSION_ID);
 
        /* Check OneNAND device */
        if (maf_id != bram_maf_id || dev_id != bram_dev_id)

diff --git a/drivers/mtd/onenand/onenand_bbt.c b/drivers/mtd/onenand/onenand_bbt.c
index 1b00dac3d7d601dc6305e52ed9067a94e7a78aaf..c8067b8f20a63404468a9f62dc569e7547475e81 100644 (file)
--- a/drivers/mtd/onenand/onenand_bbt.c
+++ b/drivers/mtd/onenand/onenand_bbt.c
@@ -100,6 +100,7 @@ static int create_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr
                                bbm->bbt[i >> 3] |= 0x03 << (i & 0x6);
                                printk(KERN_WARNING "Bad eraseblock %d at 0x%08x\n",
                                        i >> 1, (unsigned int) from);
+                               mtd->ecc_stats.badblocks++;
                                break;
                        }
                }

diff --git a/include/linux/mtd/onenand_regs.h b/include/linux/mtd/onenand_regs.h
index 9e409fe6ded6ab76ed7d52507f47870a1bc11bfb..e31c8f5d42712601744823dd22c5f31be157f333 100644 (file)
--- a/include/linux/mtd/onenand_regs.h
+++ b/include/linux/mtd/onenand_regs.h
@@ -179,6 +179,7 @@
  * ECC Status Reigser FF00h (R)
  */
 #define ONENAND_ECC_1BIT               (1 << 0)
+#define ONENAND_ECC_1BIT_ALL           (0x5555)
 #define ONENAND_ECC_2BIT               (1 << 1)
 #define ONENAND_ECC_2BIT_ALL           (0xAAAA)