[PATCH 04/20] mtd: nand: ecc-bch: Stop exporting the private structure
Adam Ford
aford173 at gmail.com
Fri Jan 15 11:06:14 EST 2021
On Fri, Jan 15, 2021 at 6:23 AM Adam Ford <aford173 at gmail.com> wrote:
>
> On Thu, Jan 14, 2021 at 9:42 AM Miquel Raynal <miquel.raynal at bootlin.com> wrote:
> >
> > Hi Adam,
> >
> > Adam Ford <aford173 at gmail.com> wrote on Tue, 12 Jan 2021 11:20:24 -0600:
> >
> > > On Tue, Jan 12, 2021 at 10:01 AM Adam Ford <aford173 at gmail.com> wrote:
> > > >
> > > > On Tue, Jan 12, 2021 at 8:35 AM Miquel Raynal <miquel.raynal at bootlin.com> wrote:
> > > > >
> > > > > Hi Adam,
> > > > >
> > > > > Miquel Raynal <miquel.raynal at bootlin.com> wrote on Mon, 11 Jan 2021
> > > > > 11:20:27 +0100:
> > > > >
> > > > > > Hi Adam,
> > > > > >
> > > > > > Adam Ford <aford173 at gmail.com> wrote on Sat, 9 Jan 2021 08:46:44 -0600:
> > > > > >
> > > > > > > On Tue, Sep 29, 2020 at 6:09 PM Miquel Raynal <miquel.raynal at bootlin.com> wrote:
> > > > > > > >
> > > > > > > > The NAND BCH control structure has nothing to do outside of this
> > > > > > > > driver, all users of the nand_bch_init/free() functions just save it
> > > > > > > > to chip->ecc.priv so do it in this driver directly and return a
> > > > > > > > regular error code instead.
> > > > > > > >
> > > > > > > > Signed-off-by: Miquel Raynal <miquel.raynal at bootlin.com>
> > > > > > > > ---
> > > > > > >
> > > > > > > Starting with this commit: 3c0fe36abebe, the kernel either doesn't
> > > > > > > build or returns errors on some omap2plus devices with the following
> > > > > > > error:
> > > > > > >
> > > > > > > nand: device found, Manufacturer ID: 0x2c, Chip ID: 0xbc
> > > > > > > nand: Micron MT29F4G16ABBDA3W
> > > > > > > nand: 512 MiB, SLC, erase size: 128 KiB, page size: 2048, OOB size: 64
> > > > > > > nand: using OMAP_ECC_BCH8_CODE_HW_DETECTION_SW
> > > > > > > Invalid ECC layout
> > > > > > > omap2-nand 30000000.nand: unable to use BCH library
> > > > > > > omap2-nand: probe of 30000000.nand failed with error -22
> > > > > > > 8<--- cut here ---
> > > > > > >
> > > > > > > There are few commits using git bisect that have build errors, so it
> > > > > > > wasn't possible for me to determine the exact commit that broke the
> > > > > > > ECC. If the build failed, I marked it as 'bad' to git bisect.
> > > > > >
> > > > > > I am sorry to hear that, I regularly rebase with a make run between each
> > > > > > pick and push my branches to a 0-day repository to have robots check
> > > > > > for such errors, but sometimes I fail.
> > > > > >
> > > > > > > Newer commits have remedied the build issue, but the Invalid ECC
> > > > > > > layout error still exists as of 5.11-RC2.
> > > > > >
> > > > > > Ok so let's focus on these.
> > > > > >
> > > > > > > Do you have any suggestions on what I can do to remedy this? I am
> > > > > > > willing to try and test.
> > > > > >
> > > > > > Glad to hear that.
> > > > > >
> > > > > > Can you share the NAND controller DT node you are using?
> > > > > >
> > > > > > Also, can you please add a few printk's like below and give me the
> > > > > > output?
> > > > >
> > > > > Will you have the time to check these soon? I am ready to help and
> > > > > would like to fix it asap.
> > > >
> > > > Sorry for the delay, I have to split my time with 3 different
> > > > projects. I am hoping to get you data later today.
> > > >
> > > Miquel,
> > >
> > > Here is the dump from my boot sequence:
> > >
> > > [ 2.629089] omap2-nand 30000000.nand: GPIO lookup for consumer rb
> > > [ 2.635253] omap2-nand 30000000.nand: using device tree for GPIO lookup
> > > [ 2.642150] of_get_named_gpiod_flags: parsed 'rb-gpios' property of node '/o)
> > > [ 2.653900] gpio gpiochip6: Persistence not supported for GPIO 0
> > > [ 2.660339] nand: device found, Manufacturer ID: 0x2c, Chip ID: 0xbc
> > > [ 2.666900] nand: Micron MT29F4G16ABBDA3W
> > > [ 2.670959] nand: 512 MiB, SLC, erase size: 128 KiB, page size: 2048, OOB si4
> > > [ 2.678710] nand: using OMAP_ECC_BCH8_CODE_HW_DETECTION_SW
> > > [ 2.684234] writesize 2048, step_size 512, nsteps 4
> > > [ 2.689300] strength 8, step size 512, code_size 13
> >
> > Until here, everything looks fine.
> >
> > > [ 2.696807] count eccbytes 0
> >
> > This is the cause of the error, the MTD OOB layout reports not ECC byte.
> >
> > Can you please check that we effectively call the large page helpers
> > (in particular nand_ooblayout_ecc_lp()) . I bet this function returns
> > -ERANGE on its first call, which reduces the eccbytes variable above to
> > zero.
>
> I will do what I can, but I am out of my element with this mtd and nand stuff.
>
> I added a printk to the beginning of nand_ooblayout_ecc_lp() and it's
> not appearing, so I wonder if nand_ooblayout_ecc_lp() is not getting
> called.
>
> I also added some printk's to the drivers/mtd/nand/raw/omap2.c to see
> what's being defined for section and ecc.steps.
>
> [ 2.621978] mtdoops: mtd device (mtddev=name/number) must be supplied
> [ 2.629699] omap2-nand 30000000.nand: GPIO lookup for consumer rb
> [ 2.635864] omap2-nand 30000000.nand: using device tree for GPIO lookup
> [ 2.642761] of_get_named_gpiod_flags: parsed 'rb-gpios' property of
> node '/ocp at 68000000/gpmc at 6e000000/nand at 0,0[0]' - status (0)
> [ 2.654510] gpio gpiochip6: Persistence not supported for GPIO 0
> [ 2.660949] nand: device found, Manufacturer ID: 0x2c, Chip ID: 0xbc
> [ 2.667510] nand: Micron MT29F4G16ABBDA3W
> [ 2.671569] nand: 512 MiB, SLC, erase size: 128 KiB, page size:
> 2048, OOB size: 64
> [ 2.679321] nand: using OMAP_ECC_BCH8_CODE_HW_DETECTION_SW
> [ 2.684844] writesize 2048, step_size 512, nsteps 4
> [ 2.689910] strength 8, step size 512, code_size 13
> [ 2.694824] nand->ecc.ctx.total = 52
> [ 2.700988] omap_sw_ooblayout_ecc section 0, chip->ecc.steps 0
>
> omap_sw_ooblayout_ecc() returns -ERANGE if section => chip->ecc.steps
> which appears to be the case here.
>
> Is it safe to assume that ecc.steps should be 4 if nsteps is 4?
>
> [ 2.707031] count eccbytes 0
> [ 2.709930] omap_sw_ooblayout_ecc section 0, chip->ecc.steps 0
> [ 2.715820] Invalid ECC layout
> [ 2.719055] omap2-nand 30000000.nand: unable to use BCH library
> [ 2.725067] omap2-nand: probe of 30000000.nand failed with error -22
> [ 2.738983] 8<--- cut here ---
>
> >
> > What is strange is that, the only reason this would happen (to my eyes)
> > is nand->ecc.ctx.total being 0. Can you please check its effective
> > value?
>
> [ 2.694824] nand->ecc.ctx.total = 52
>
> >
> > I do not see the immediate reason because nand->ecc.ctx.total is set to
> > nsteps (4) * code_size (13) right before calling
> > mtd_ooblayout_count_eccbytes().
> >
> > Can you please verify my sayings and perhaps tackle the root cause of
> > this issue? Please do not hesitate to ask questions, I'll do my best to
> > help because this is a critical section that is not only breaking
> > OMAP boards, unfortunately.
I appear to have the NAND flash working with the following patch:
@@ -247,11 +253,21 @@ int nand_ecc_sw_bch_init_ctx(struct nand_device *nand)
nand->ecc.ctx.priv = engine_conf;
nand->ecc.ctx.total = nsteps * code_size;
+ struct nand_chip *chip = mtd_to_nand(mtd);
+ chip->ecc.steps = nsteps;
+ chip->ecc.size = conf->step_size;
I am guessing it's not exactly what you want, but appears that the
ecc.steps and ecc.size wasn't getting propagated to the mtd layer, so
when omap_sw_ooblayout_ecc() was called, those fields were blank.
If you have a suggestion on how you want this implemented, I can push a patch.
adam
> >
> > Thanks,
> > Miquèl
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