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, 7 insertions, 3 deletions

diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
index a1048c7c5d2c..1b346474dba8 100644
--- a/drivers/mtd/nand/denali.c
+++ b/drivers/mtd/nand/denali.c
@@ -924,9 +924,10 @@ bool is_erased(uint8_t *buf, int len)
 #define ECC_LAST_ERR(x)         ((x) & ERR_CORRECTION_INFO__LAST_ERR_INFO)
 
 static bool handle_ecc(struct denali_nand_info *denali, uint8_t *buf,
-                                        uint32_t irq_status)
+                       uint32_t irq_status, unsigned int *max_bitflips)
 {
         bool check_erased_page = false;
+        unsigned int bitflips = 0;
 
         if (irq_status & INTR_STATUS__ECC_ERR) {
                 /* read the ECC errors. we'll ignore them for now */
@@ -965,6 +966,7 @@ static bool handle_ecc(struct denali_nand_info *denali, uint8_t *buf,
                                         /* correct the ECC error */
                                         buf[offset] ^= err_correction_value;
                                         denali->mtd.ecc_stats.corrected++;
+                                        bitflips++;
                                 }
                         } else {
                                 /* if the error is not correctable, need to
@@ -984,6 +986,7 @@ static bool handle_ecc(struct denali_nand_info *denali, uint8_t *buf,
                 clear_interrupts(denali);
                 denali_set_intr_modes(denali, true);
         }
+        *max_bitflips = bitflips;
         return check_erased_page;
 }
 
@@ -1121,6 +1124,7 @@ static int denali_read_oob(struct mtd_info *mtd, struct nand_chip *chip,
 static int denali_read_page(struct mtd_info *mtd, struct nand_chip *chip,
                             uint8_t *buf, int page)
 {
+        unsigned int max_bitflips;
         struct denali_nand_info *denali = mtd_to_denali(mtd);
 
         dma_addr_t addr = denali->buf.dma_buf;
@@ -1153,7 +1157,7 @@ static int denali_read_page(struct mtd_info *mtd, struct nand_chip *chip,
 
         memcpy(buf, denali->buf.buf, mtd->writesize);
 
-        check_erased_page = handle_ecc(denali, buf, irq_status);
+        check_erased_page = handle_ecc(denali, buf, irq_status, &max_bitflips);
         denali_enable_dma(denali, false);
 
         if (check_erased_page) {
@@ -1167,7 +1171,7 @@ static int denali_read_page(struct mtd_info *mtd, struct nand_chip *chip,
                                 denali->mtd.ecc_stats.failed++;
                 }
         }
-        return 0;
+        return max_bitflips;
 }
 
 static int denali_read_page_raw(struct mtd_info *mtd, struct nand_chip *chip,