---

yaml
---
r: 298148
b: refs/heads/master
c: 519300c
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 994c8409c4591983898182bfb5a0368d3daf1fc1
+refs/heads/master: 519300cfe18ee8dcf0b1e7a38564b61b70e4ee86

trunk/drivers/mtd/nand/fsmc_nand.c

@@ -391,6 +391,20 @@ static int fsmc_read_hwecc_ecc1(struct mtd_info *mtd, const uint8_t *data,
 	return 0;
 }
 
+/* Count the number of 0's in buff upto a max of max_bits */
+static int count_written_bits(uint8_t *buff, int size, int max_bits)
+{
+	int k, written_bits = 0;
+
+	for (k = 0; k < size; k++) {
+		written_bits += hweight8(~buff[k]);
+		if (written_bits > max_bits)
+			break;
+	}
+
+	return written_bits;
+}
+
 /*
  * fsmc_read_page_hwecc
  * @mtd:	mtd info structure
@@ -426,7 +440,6 @@ static int fsmc_read_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
 	uint8_t *oob = (uint8_t *)&ecc_oob[0];
 
 	for (i = 0, s = 0; s < eccsteps; s++, i += eccbytes, p += eccsize) {
-
 		chip->cmdfunc(mtd, NAND_CMD_READ0, s * eccsize, page);
 		chip->ecc.hwctl(mtd, NAND_ECC_READ);
 		chip->read_buf(mtd, p, eccsize);
@@ -447,7 +460,7 @@ static int fsmc_read_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
 			j += len;
 		}
 
-		memcpy(&ecc_code[i], oob, 13);
+		memcpy(&ecc_code[i], oob, chip->ecc.bytes);
 		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
 
 		stat = chip->ecc.correct(mtd, p, &ecc_code[i], &ecc_calc[i]);
@@ -475,14 +488,49 @@ static int fsmc_correct_data(struct mtd_info *mtd, uint8_t *dat,
 {
 	struct fsmc_nand_data *host = container_of(mtd,
 					struct fsmc_nand_data, mtd);
+	struct nand_chip *chip = mtd->priv;
 	struct fsmc_regs *regs = host->regs_va;
 	unsigned int bank = host->bank;
 	uint16_t err_idx[8];
 	uint64_t ecc_data[2];
 	uint32_t num_err, i;
 
+	num_err = (readl(&regs->bank_regs[bank].sts) >> 10) & 0xF;
+
+	/* no bit flipping */
+	if (likely(num_err == 0))
+		return 0;
+
+	/* too many errors */
+	if (unlikely(num_err > 8)) {
+		/*
+		 * This is a temporary erase check. A newly erased page read
+		 * would result in an ecc error because the oob data is also
+		 * erased to FF and the calculated ecc for an FF data is not
+		 * FF..FF.
+		 * This is a workaround to skip performing correction in case
+		 * data is FF..FF
+		 *
+		 * Logic:
+		 * For every page, each bit written as 0 is counted until these
+		 * number of bits are greater than 8 (the maximum correction
+		 * capability of FSMC for each 512 + 13 bytes)
+		 */
+
+		int bits_ecc = count_written_bits(read_ecc, chip->ecc.bytes, 8);
+		int bits_data = count_written_bits(dat, chip->ecc.size, 8);
+
+		if ((bits_ecc + bits_data) <= 8) {
+			if (bits_data)
+				memset(dat, 0xff, chip->ecc.size);
+			return bits_data;
+		}
+
+		return -EBADMSG;
+	}
+
 	/* The calculated ecc is actually the correction index in data */
-	memcpy(ecc_data, calc_ecc, 13);
+	memcpy(ecc_data, calc_ecc, chip->ecc.bytes);
 
 	/*
 	 * ------------------- calc_ecc[] bit wise -----------|--13 bits--|
@@ -513,7 +561,7 @@ static int fsmc_correct_data(struct mtd_info *mtd, uint8_t *dat,
 		change_bit(0, (unsigned long *)&err_idx[i]);
 		change_bit(1, (unsigned long *)&err_idx[i]);
 
-		if (err_idx[i] <= 512 * 8) {
+		if (err_idx[i] <= chip->ecc.size * 8) {
 			change_bit(err_idx[i], (unsigned long *)dat);
 			i++;
 		}