[PATCH] nand gpmi fix erased block bitflip counting

[w.cappelle at televic.com]

From: Wouter Cappelle <w.cappelle at televic.com>

---
 drivers/mtd/nand/gpmi-nand/gpmi-nand.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
index 8339d4f..6ae118c 100644
--- a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
+++ b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
@@ -1217,6 +1217,7 @@ static bool gpmi_erased_check(struct gpmi_nand_data *this,
 	int base = geo->ecc_chunkn_size * chunk;
 	unsigned int flip_bits = 0, flip_bits_noecc = 0;
 	uint64_t *buf = (uint64_t *)this->data_buffer_dma;
+	unsigned char *chunkbuf =(unsigned char*) this->data_buffer_dma;
 	unsigned int threshold;
 	int i;
 
@@ -1224,13 +1225,6 @@ static bool gpmi_erased_check(struct gpmi_nand_data *this,
 	if (threshold > geo->ecc_strength)
 		threshold = geo->ecc_strength;
 
-	/* Count bitflips */
-	for (i = 0; i < geo->ecc_chunkn_size; i++) {
-		flip_bits += hweight8(~data[base + i]);
-		if (flip_bits > threshold)
-			return false;
-	}
-
 	/*
 	 * Read out the whole page with ECC disabled, and check it again,
 	 * This is more strict then just read out a chunk, and it makes
@@ -1246,6 +1240,12 @@ static bool gpmi_erased_check(struct gpmi_nand_data *this,
 			return false;
 	}
 
+	/* Count bitflips in the current chunk for correct stats reporting */
+	for (i = 0; i < geo->ecc_chunkn_size; i++) {
+		flip_bits += hweight8(~chunkbuf[base + i]);
+	}
+
+
 	/* Tell the upper layer the bitflips we corrected. */
 	mtd->ecc_stats.corrected += flip_bits;
 	*max_bitflips = max_t(unsigned int, *max_bitflips, flip_bits);
-- 
2.7.4