mtd: flash drivers set ecc strength

Flash device drivers initialize 'ecc_strength' in struct mtd_info, which is the
maximum number of bit errors that can be corrected in one writesize region.

Drivers using the nand interface intitialize 'strength' in struct nand_ecc_ctrl,
which is the maximum number of bit errors that can be corrected in one ecc step.
Nand infrastructure code translates this to 'ecc_strength'.

Also for nand drivers, the nand infrastructure code sets ecc.strength for ecc
modes NAND_ECC_SOFT, NAND_ECC_SOFT_BCH, and NAND_ECC_NONE.  It is set in the
driver for all other modes.

Signed-off-by: Mike Dunn <mikedunn@newsguy.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, 1 deletions

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 1e907dc8638a..8008853756c9 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -3350,6 +3350,7 @@ int nand_scan_tail(struct mtd_info *mtd)
                 if (!chip->ecc.size)
                         chip->ecc.size = 256;
                 chip->ecc.bytes = 3;
+                chip->ecc.strength = 1;
                 break;
 
         case NAND_ECC_SOFT_BCH:
@@ -3384,6 +3385,8 @@ int nand_scan_tail(struct mtd_info *mtd)
                         pr_warn("BCH ECC initialization failed!\n");
                         BUG();
                 }
+                chip->ecc.strength =
+                        chip->ecc.bytes*8 / fls(8*chip->ecc.size);
                 break;
 
         case NAND_ECC_NONE:
@@ -3397,6 +3400,7 @@ int nand_scan_tail(struct mtd_info *mtd)
                 chip->ecc.write_oob = nand_write_oob_std;
                 chip->ecc.size = mtd->writesize;
                 chip->ecc.bytes = 0;
+                chip->ecc.strength = 0;
                 break;
 
         default:
@@ -3478,8 +3482,9 @@ int nand_scan_tail(struct mtd_info *mtd)
         mtd->_block_markbad = nand_block_markbad;
         mtd->writebufsize = mtd->writesize;
 
-        /* propagate ecc.layout to mtd_info */
+        /* propagate ecc info to mtd_info */
         mtd->ecclayout = chip->ecc.layout;
+        mtd->ecc_strength = chip->ecc.strength * chip->ecc.steps;
 
         /* Check, if we should skip the bad block table scan */
         if (chip->options & NAND_SKIP_BBTSCAN)