Re: [PATCH] mtd: gpmi: Always report ECC stats and return max_bitflips

[Huang Shijie <b32955@freescale.com>]

于 2012年12月04日 03:48, Zach Sadecki 写道:
> Always report corrected and failed ECC stats back up to the MTD layer. 
> Also
> return max_bitflips from read_page() as is expected from NAND drivers 
> now.
>
> Signed-off-by: Zach Sadecki <zsadecki@itwatchdogs.com>
> ---
> drivers/mtd/nand/gpmi-nand/gpmi-nand.c | 27 ++++++++-------------------
> 1 file changed, 8 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c 
> b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
> index d79696b..fe10c53 100644
> --- a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
> +++ b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
> @@ -914,8 +914,7 @@ static int gpmi_ecc_read_page(struct mtd_info 
> *mtd, struct nand_chip *chip,
> dma_addr_t auxiliary_phys;
> unsigned int i;
> unsigned char *status;
> - unsigned int failed;
> - unsigned int corrected;
> + unsigned int max_bitflips = 0;
> int ret;
> pr_debug("page number is : %d\n", page);
> @@ -939,35 +938,25 @@ static int gpmi_ecc_read_page(struct mtd_info 
> *mtd, struct nand_chip *chip,
> payload_virt, payload_phys);
> if (ret) {
> pr_err("Error in ECC-based read: %d\n", ret);
> - goto exit_nfc;
> + return ret;
> }
> /* handle the block mark swapping */
> block_mark_swapping(this, payload_virt, auxiliary_virt);
> /* Loop over status bytes, accumulating ECC status. */
> - failed = 0;
> - corrected = 0;
> - status = auxiliary_virt + nfc_geo->auxiliary_status_offset;
> + status = auxiliary_virt + nfc_geo->auxiliary_status_offset;
> for (i = 0; i < nfc_geo->ecc_chunk_count; i++, status++) {
> if ((*status == STATUS_GOOD) || (*status == STATUS_ERASED))
> continue;
> if (*status == STATUS_UNCORRECTABLE) {
> - failed++;
> + mtd->ecc_stats.failed++;
> continue;
> }
> - corrected += *status;
> - }
> -
> - /*
> - * Propagate ECC status to the owning MTD only when failed or
> - * corrected times nearly reaches our ECC correction threshold.
> - */
> - if (failed || corrected >= (nfc_geo->ecc_strength - 1)) {
> - mtd->ecc_stats.failed += failed;
> - mtd->ecc_stats.corrected += corrected;
> + mtd->ecc_stats.corrected += *status;
> + max_bitflips = max_t(unsigned int, max_bitflips, *status);

Does the max_bitflips stand for the whole page's bitfips ? or just the 
bitfips of one part of the page?
The gpmi driver splits a page into several parts when it does the ECC.

thanks
Huang Shijie


> }
> if (oob_required) {
> @@ -989,8 +978,8 @@ static int gpmi_ecc_read_page(struct mtd_info 
> *mtd, struct nand_chip *chip,
> this->payload_virt, this->payload_phys,
> nfc_geo->payload_size,
> payload_virt, payload_phys);
> -exit_nfc:
> - return ret;
> +
> + return max_bitflips;
> }
> static int gpmi_ecc_write_page(struct mtd_info *mtd, struct nand_chip 
> *chip,