mtd/nand:Fix wrong usage of is_blank() in fsl_ifc_run_command

Freescale IFC NAND Machine calculates ECC on 512byte sector and same is used in
fsl_ifc_run_command() during ECC status verification. Also this sector is passed
to is_blank() for blank checking. It is wrong at first place because
is_blank()'s implementation checks for Page size and OOB area size.
is_blank() should be called per page for main and OOB area verification.

Variables name are redefined to avoid confusion between buffer and ecc sector.

Signed-off-by: Poonam Aggrwal <poonam.aggrwal@freescale.com>
Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>

diff --git a/drivers/mtd/nand/fsl_ifc_nand.c b/drivers/mtd/nand/fsl_ifc_nand.c
index 36e1baeb497660b4e8da27eb1803573b9095fa24..5cac78b2968567a500a2db3155083f9661b189e9 100644 (file)
--- a/drivers/mtd/nand/fsl_ifc_nand.c
+++ b/drivers/mtd/nand/fsl_ifc_nand.c
@@ -1,6 +1,6 @@
 /* Integrated Flash Controller NAND Machine Driver
  *
- * Copyright (c) 2011 Freescale Semiconductor, Inc
+ * Copyright (c) 2012 Freescale Semiconductor, Inc
  *
  * Authors: Dipen Dudhat <Dipen.Dudhat@freescale.com>
  *
@@ -221,24 +221,11 @@ static int check_read_ecc(struct mtd_info *mtd, struct fsl_ifc_ctrl *ctrl,
                          u32 *eccstat, unsigned int bufnum)
 {
        u32 reg = eccstat[bufnum / 4];
-       int errors = (reg >> ((3 - bufnum % 4) * 8)) & 15;
-
-       if (errors == 15) { /* uncorrectable */
-               /* Blank pages fail hw ECC checks */
-               if (is_blank(mtd, ctrl, bufnum))
-                       return 1;
-
-               /*
-                * We disable ECCER reporting in hardware due to
-                * erratum IFC-A002770 -- so report it now if we
-                * see an uncorrectable error in ECCSTAT.
-                */
-               ctrl->status |= IFC_NAND_EVTER_STAT_ECCER;
-       } else if (errors > 0) {
-               mtd->ecc_stats.corrected += errors;
-       }
+       int errors;
 
-       return 0;
+       errors = (reg >> ((3 - bufnum % 4) * 8)) & 15;
+
+       return errors;
 }
 
 /*
@@ -279,16 +266,33 @@ static int fsl_ifc_run_command(struct mtd_info *mtd)
                printf("%s: Write Protect Error\n", __func__);
 
        if (ctrl->eccread) {
-               int bufperpage = mtd->writesize / 512;
-               int bufnum = (ctrl->page & priv->bufnum_mask) * bufperpage;
-               int bufnum_end = bufnum + bufperpage - 1;
+               int errors;
+               int bufnum = ctrl->page & priv->bufnum_mask;
+               int sector = bufnum * chip->ecc.steps;
+               int sector_end = sector + chip->ecc.steps - 1;
 
-               for (i = bufnum / 4; i <= bufnum_end / 4; i++)
+               for (i = sector / 4; i <= sector_end / 4; i++)
                        eccstat[i] = in_be32(&ifc->ifc_nand.nand_eccstat[i]);
 
-               for (i = bufnum; i <= bufnum_end; i++) {
-                       if (check_read_ecc(mtd, ctrl, eccstat, i))
+               for (i = sector; i <= sector_end; i++) {
+                       errors = check_read_ecc(mtd, ctrl, eccstat, i);
+
+                       if (errors == 15) {
+                               /*
+                                * Uncorrectable error.
+                                * OK only if the whole page is blank.
+                                *
+                                * We disable ECCER reporting due to erratum
+                                * IFC-A002770 -- so report it now if we
+                                * see an uncorrectable error in ECCSTAT.
+                                */
+                               if (!is_blank(mtd, ctrl, bufnum))
+                                       ctrl->status |=
+                                               IFC_NAND_EVTER_STAT_ECCER;
                                break;
+                       }
+
+                       mtd->ecc_stats.corrected += errors;
                }
 
                ctrl->eccread = 0;