+ others
On Thu, Sep 03, 2015 at 06:03:42PM +0200, Boris Brezillon wrote:
> Some drivers are manually checking for 'erased pages' while correcting
> ECC bytes.
> This logic is now done by the core infrastructure, and can thus be removed
> from those drivers.
>
> Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>
> ---
> drivers/mtd/nand/davinci_nand.c | 8 --------
> drivers/mtd/nand/diskonchip.c | 32 ++------------------------------
> drivers/mtd/nand/jz4740_nand.c | 18 ------------------
> 3 files changed, 2 insertions(+), 56 deletions(-)
>
> diff --git a/drivers/mtd/nand/davinci_nand.c b/drivers/mtd/nand/davinci_nand.c
> index 816ef53..0d6adbe 100644
> --- a/drivers/mtd/nand/davinci_nand.c
> +++ b/drivers/mtd/nand/davinci_nand.c
> @@ -316,14 +316,6 @@ static int nand_davinci_correct_4bit(struct mtd_info *mtd,
> unsigned num_errors, corrected;
> unsigned long timeo;
>
> - /* All bytes 0xff? It's an erased page; ignore its ECC. */
> - for (i = 0; i < 10; i++) {
> - if (ecc_code[i] != 0xff)
> - goto compare;
> - }
> - return 0;
> -
> -compare:
> /* Unpack ten bytes into eight 10 bit values. We know we're
> * little-endian, and use type punning for less shifting/masking.
> */
> diff --git a/drivers/mtd/nand/diskonchip.c b/drivers/mtd/nand/diskonchip.c
> index 7da266a..eb65769 100644
> --- a/drivers/mtd/nand/diskonchip.c
> +++ b/drivers/mtd/nand/diskonchip.c
> @@ -936,37 +936,9 @@ static int doc200x_correct_data(struct mtd_info *mtd, u_char *dat,
> calc_ecc[i] = ReadDOC_(docptr, DoC_Mplus_ECCSyndrome0 + i);
> else
> calc_ecc[i] = ReadDOC_(docptr, DoC_ECCSyndrome0 + i);
> - if (calc_ecc[i] != empty_read_syndrome[i])
> - emptymatch = 0;
> }
> - /* If emptymatch=1, the read syndrome is consistent with an
> - all-0xff data and stored ecc block. Check the stored ecc. */
> - if (emptymatch) {
> - for (i = 0; i < 6; i++) {
> - if (read_ecc[i] == 0xff)
> - continue;
> - emptymatch = 0;
> - break;
> - }
> - }
> - /* If emptymatch still =1, check the data block. */
> - if (emptymatch) {
> - /* Note: this somewhat expensive test should not be triggered
> - often. It could be optimized away by examining the data in
> - the readbuf routine, and remembering the result. */
> - for (i = 0; i < 512; i++) {
> - if (dat[i] == 0xff)
> - continue;
> - emptymatch = 0;
> - break;
> - }
> - }
> - /* If emptymatch still =1, this is almost certainly a freshly-
> - erased block, in which case the ECC will not come out right.
> - We'll suppress the error and tell the caller everything's
> - OK. Because it is. */
> - if (!emptymatch)
> - ret = doc_ecc_decode(rs_decoder, dat, calc_ecc);
> +
> + ret = doc_ecc_decode(rs_decoder, dat, calc_ecc);
> if (ret > 0)
> printk(KERN_ERR "doc200x_correct_data corrected %d errors\n", ret);
> }
I see new warnings:
drivers/mtd/nand/diskonchip.c: At top level:
drivers/mtd/nand/diskonchip.c: In function ‘doc200x_correct_data’:
drivers/mtd/nand/diskonchip.c:915:6: warning: unused variable ‘emptymatch’ [-Wunused-variable]
int emptymatch = 1;
^
drivers/mtd/nand/diskonchip.c:79:15: warning: ‘empty_read_syndrome’ defined but not used [-Wunused-variable]
static u_char empty_read_syndrome[6] = { 0x26, 0xff, 0x6d, 0x47, 0x73, 0x7a };
^
I'd also like test results for these drivers before doing this. And I'm
not sure how to find good testers for these drivers, even it users still
exist.
> diff --git a/drivers/mtd/nand/jz4740_nand.c b/drivers/mtd/nand/jz4740_nand.c
> index ba44af3..4d73276 100644
> --- a/drivers/mtd/nand/jz4740_nand.c
> +++ b/drivers/mtd/nand/jz4740_nand.c
> @@ -224,24 +224,6 @@ static int jz_nand_correct_ecc_rs(struct mtd_info *mtd, uint8_t *dat,
> uint32_t t;
> unsigned int timeout = 1000;
>
> - t = read_ecc[0];
> -
> - if (t == 0xff) {
> - for (i = 1; i < 9; ++i)
> - t &= read_ecc[i];
> -
> - t &= dat[0];
> - t &= dat[nand->chip.ecc.size / 2];
> - t &= dat[nand->chip.ecc.size - 1];
> -
> - if (t == 0xff) {
> - for (i = 1; i < nand->chip.ecc.size - 1; ++i)
> - t &= dat[i];
> - if (t == 0xff)
> - return 0;
> - }
> - }
> -
> for (i = 0; i < 9; ++i)
> writeb(read_ecc[i], nand->base + JZ_REG_NAND_PAR0 + i);
>
> --
> 1.9.1
>
