lkml.org 
[lkml]   [2021]   [Sep]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 4/8] Revert "mtd: rawnand: tmio: Fix external use of SW Hamming ECC helper"
    Date
    This reverts commit 6a4c5ada577467a5f79e06f2c5e69c09983c22fb.

    Before the introduction of the ECC framework infrastructure, many
    drivers used the ->calculate/correct() Hamming helpers directly. The
    point of this framework was to avoid this kind of hackish calls and use a
    proper and generic API but it is true that in certain cases, drivers
    still need to use these helpers in order to do ECC computations on
    behalf of their limited hardware.

    Right after the introduction of the ECC engine core introduction, it was
    spotted that it was not possible to use the shiny rawnand software ECC
    helpers so easily because an ECC engine object should have been
    allocated and initialized first. While this works well in most cases,
    for these drivers just leveraging the power of a single helper in
    conjunction with some pretty old and limited hardware, it did not fit.

    The idea back then was to declare intermediate helpers which would make
    use of the exported software ECC engine bare functions while keeping the
    rawnand layer compatibility. As there was already functions with the
    rawnand_sw_hamming_ prefix it was decided to declare new local helpers
    for this purpose in each driver needing one.

    Besides being far from optimal, this design choice was blamed by Linus
    when he pulled the "fixes" pull request [1] so that is why now it is
    time to clean this mess up.

    The implementation of the rawnand_ecc_sw_* helpers has now been enhanced
    to support both cases, when the ECC object is instantiated and when it is
    not. This way, we can still use the existing and exported rawnand
    helpers while avoiding the need for each driver to declare its own
    helper, thus this fix from [2] can now be safely reverted.

    [1] https://lore.kernel.org/lkml/CAHk-=wh_ZHF685Fni8V9is17mj=pFisUaZ_0=gq6nbK+ZcyQmg@mail.gmail.com/
    [2] https://lore.kernel.org/linux-mtd/20210413161840.345208-1-miquel.raynal@bootlin.com

    Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
    ---
    drivers/mtd/nand/raw/tmio_nand.c | 8 +++-----
    1 file changed, 3 insertions(+), 5 deletions(-)

    diff --git a/drivers/mtd/nand/raw/tmio_nand.c b/drivers/mtd/nand/raw/tmio_nand.c
    index 6d93dd31969b..de8e919d0ebe 100644
    --- a/drivers/mtd/nand/raw/tmio_nand.c
    +++ b/drivers/mtd/nand/raw/tmio_nand.c
    @@ -34,7 +34,6 @@
    #include <linux/interrupt.h>
    #include <linux/ioport.h>
    #include <linux/mtd/mtd.h>
    -#include <linux/mtd/nand-ecc-sw-hamming.h>
    #include <linux/mtd/rawnand.h>
    #include <linux/mtd/partitions.h>
    #include <linux/slab.h>
    @@ -293,12 +292,11 @@ static int tmio_nand_correct_data(struct nand_chip *chip, unsigned char *buf,
    int r0, r1;

    /* assume ecc.size = 512 and ecc.bytes = 6 */
    - r0 = ecc_sw_hamming_correct(buf, read_ecc, calc_ecc,
    - chip->ecc.size, false);
    + r0 = rawnand_sw_hamming_correct(chip, buf, read_ecc, calc_ecc);
    if (r0 < 0)
    return r0;
    - r1 = ecc_sw_hamming_correct(buf + 256, read_ecc + 3, calc_ecc + 3,
    - chip->ecc.size, false);
    + r1 = rawnand_sw_hamming_correct(chip, buf + 256, read_ecc + 3,
    + calc_ecc + 3);
    if (r1 < 0)
    return r1;
    return r0 + r1;
    --
    2.27.0
    \
     
     \ /
      Last update: 2021-09-29 00:15    [W:3.835 / U:0.188 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site