mtd: pxa3xx_nand: Fix blank page ECC mismatch

This bug was introduced in f8155a40 ("mtd: pxa3xx_nand: rework irq
logic") and causes the PXA3xx NAND controller fail to operate with NAND
flash that has empty pages. According to the comment in this block, the
hardware controller will report a double-bit error for empty pages,
which can and must be ignored.

This patch restores the original behaviour of the driver.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Acked-by: Lei Wen <leiwen@marvell.com>
Cc: Haojian Zhuang <haojian.zhuang@marvell.com>
Cc: David Woodhouse <David.Woodhouse@intel.com>
Cc: stable@kernel.org [2.6.38+]
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

diff --git a/drivers/mtd/nand/pxa3xx_nand.c b/drivers/mtd/nand/pxa3xx_nand.c
index 9fde1399af9169616bff0d5c1c9564b6573203b4..5c3af2f72a62ccca6bddc86fa244cef0b1392e97 100644 (file)
--- a/drivers/mtd/nand/pxa3xx_nand.c
+++ b/drivers/mtd/nand/pxa3xx_nand.c
@@ -685,6 +685,8 @@ static int pxa3xx_nand_read_page_hwecc(struct mtd_info *mtd,
                 * OOB, ignore such double bit errors
                 */
                if (is_buf_blank(buf, mtd->writesize))
+                       info->retcode = ERR_NONE;
+               else
                        mtd->ecc_stats.failed++;
        }