mtd: nand: read_page() returns max_bitflips

The ecc.read_page() method for nand drivers is changed to return the maximum
number of bitflips that were corrected on any one region covering an ecc step,
This patch doesn't change what the nand code returns to mtd.

This v2 includes the change to the fsl_ifc_nand driver requested by Scott¹.

¹ http://lists.infradead.org/pipermail/linux-mtd/2012-April/040883.html

Signed-off-by: Mike Dunn <mikedunn@newsguy.com>
Acked-by (freescale changes): Scott Wood <scottwood@freescale.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 6 insertions, 3 deletions

diff --git a/drivers/mtd/nand/fsmc_nand.c b/drivers/mtd/nand/fsmc_nand.c
index 9d7f4171e077..6bf59fdde263 100644
--- a/drivers/mtd/nand/fsmc_nand.c
+++ b/drivers/mtd/nand/fsmc_nand.c
@@ -720,6 +720,7 @@ static int fsmc_read_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
          */
         uint16_t ecc_oob[7];
         uint8_t *oob = (uint8_t *)&ecc_oob[0];
+        unsigned int max_bitflips = 0;
 
         for (i = 0, s = 0; s < eccsteps; s++, i += eccbytes, p += eccsize) {
                 chip->cmdfunc(mtd, NAND_CMD_READ0, s * eccsize, page);
@@ -748,13 +749,15 @@ static int fsmc_read_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
                 chip->ecc.calculate(mtd, p, &ecc_calc[i]);
 
                 stat = chip->ecc.correct(mtd, p, &ecc_code[i], &ecc_calc[i]);
-                if (stat < 0)
+                if (stat < 0) {
                         mtd->ecc_stats.failed++;
-                else
+                } else {
                         mtd->ecc_stats.corrected += stat;
+                        max_bitflips = max_t(unsigned int, max_bitflips, stat);
+                }
         }
 
-        return 0;
+        return max_bitflips;
 }
 
 /*