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From:   =?UTF-8?B?w4FsdmFybyBGZXJuw6FuZGV6IFJvamFz?= <noltari@gmail.com>
Date:   Fri, 24 Mar 2023 12:21:11 +0100
Message-ID: <CAKR-sGc3R_k_+-hzv5DOOeRO-5rHL1k_dq7mpZLcv=FgZ1Moug@mail.gmail.com>
Subject: Re: [PATCH 1/2] dt-bindings: mtd: nand: Macronix: document new binding
To:     Miquel Raynal <miquel.raynal@bootlin.com>
Cc:     richard@nod.at, vigneshr@ti.com, robh+dt@kernel.org,
        krzysztof.kozlowski+dt@linaro.org, masonccyang@mxic.com.tw,
        linux-mtd@lists.infradead.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org
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El vie, 24 mar 2023 a las 11:49, Miquel Raynal
(<miquel.raynal@bootlin.com>) escribi=C3=B3:
>
> Hi =C3=81lvaro,
>
> noltari@gmail.com wrote on Fri, 24 Mar 2023 11:31:17 +0100:
>
> > Hi Miqu=C3=A8l,
> >
> > El vie, 24 mar 2023 a las 10:40, Miquel Raynal
> > (<miquel.raynal@bootlin.com>) escribi=C3=B3:
> > >
> > > Hi =C3=81lvaro,
> > >
> > > noltari@gmail.com wrote on Thu, 23 Mar 2023 13:45:09 +0100:
> > >
> > > > Add new "mxic,disable-block-protection" binding documentation.
> > > > This binding allows disabling block protection support for those de=
vices not
> > > > supporting it.
> > > >
> > > > Signed-off-by: =C3=81lvaro Fern=C3=A1ndez Rojas <noltari@gmail.com>
> > > > ---
> > > >  Documentation/devicetree/bindings/mtd/nand-macronix.txt | 3 +++
> > > >  1 file changed, 3 insertions(+)
> > > >
> > > > diff --git a/Documentation/devicetree/bindings/mtd/nand-macronix.tx=
t b/Documentation/devicetree/bindings/mtd/nand-macronix.txt
> > > > index ffab28a2c4d1..03f65ca32cd3 100644
> > > > --- a/Documentation/devicetree/bindings/mtd/nand-macronix.txt
> > > > +++ b/Documentation/devicetree/bindings/mtd/nand-macronix.txt
> > > > @@ -16,6 +16,9 @@ in children nodes.
> > > >  Required NAND chip properties in children mode:
> > > >  - randomizer enable: should be "mxic,enable-randomizer-otp"
> > > >
> > > > +Optional NAND chip properties in children mode:
> > > > +- block protection disable: should be "mxic,disable-block-protecti=
on"
> > > > +
> > >
> > > Besides the fact that nowadays we prefer to see binding conversions t=
o
> > > yaml before adding anything, I don't think this will fly.
> > >
> > > I'm not sure exactly what "disable block protection" means, we
> > > already have similar properties like "lock" and "secure-regions", not
> > > sure they will fit but I think it's worth checking.
> >
> > As explained in 2/2, commit 03a539c7a118 introduced a regression on
> > Sercomm H500-s (BCM63268) OpenWrt devices with Macronix MX30LF1G18AC
> > which hangs the device.
> >
> > This is the log with block protection disabled:
> > [    0.495831] bcm6368_nand 10000200.nand: there is not valid maps for
> > state default
> > [    0.504995] nand: device found, Manufacturer ID: 0xc2, Chip ID: 0xf1
> > [    0.511526] nand: Macronix MX30LF1G18AC
> > [    0.515586] nand: 128 MiB, SLC, erase size: 128 KiB, page size:
> > 2048, OOB size: 64
> > [    0.523516] bcm6368_nand 10000200.nand: detected 128MiB total,
> > 128KiB blocks, 2KiB pages, 16B OOB, 8-bit, BCH-4
> > [    0.535912] Bad block table found at page 65472, version 0x01
> > [    0.544268] Bad block table found at page 65408, version 0x01
> > [    0.954329] 9 fixed-partitions partitions found on MTD device brcmna=
nd.0
> > ...
> >
> > This is the log with block protection enabled:
> > [    0.495095] bcm6368_nand 10000200.nand: there is not valid maps for
> > state default
> > [    0.504249] nand: device found, Manufacturer ID: 0xc2, Chip ID: 0xf1
> > [    0.510772] nand: Macronix MX30LF1G18AC
> > [    0.514874] nand: 128 MiB, SLC, erase size: 128 KiB, page size:
> > 2048, OOB size: 64
> > [    0.522780] bcm6368_nand 10000200.nand: detected 128MiB total,
> > 128KiB blocks, 2KiB pages, 16B OOB, 8-bit, BCH-4
> > [    0.539687] Bad block table not found for chip 0
> > [    0.550153] Bad block table not found for chip 0
> > [    0.555069] Scanning device for bad blocks
> > [    0.601213] CPU 1 Unable to handle kernel paging request at virtual
> > address 10277f00, epc =3D=3D 8039ce70, ra =3D=3D 8016ad50
> > *** Device hangs ***
> >
> > Enabling macronix_nand_block_protection_support() makes the device
> > unable to detect the bad block table and hangs it when trying to scan
> > for bad blocks.
>
> Please trace nand_macronix.c and look:
> - are the get_features and set_features really supported by the
>   controller driver?

This is what I could find by debugging:
[    0.494993] bcm6368_nand 10000200.nand: there is not valid maps for
state default
[    0.505375] nand: device found, Manufacturer ID: 0xc2, Chip ID: 0xf1
[    0.512077] nand: Macronix MX30LF1G18AC
[    0.515994] nand: 128 MiB, SLC, erase size: 128 KiB, page size:
2048, OOB size: 64
[    0.523928] bcm6368_nand 10000200.nand: detected 128MiB total,
128KiB blocks, 2KiB pages, 16B OOB, 8-bit, BCH-4
[    0.534415] bcm6368_nand 10000200.nand: ll_op cmd 0xa00ee
[    0.539988] bcm6368_nand 10000200.nand: ll_op cmd 0x600a0
[    0.545659] bcm6368_nand 10000200.nand: ll_op cmd 0x10000
[    0.551214] bcm6368_nand 10000200.nand: NAND_CMD_GET_FEATURES =3D 0x00
[    0.557843] bcm6368_nand 10000200.nand: ll_op cmd 0x10000
[    0.563475] bcm6368_nand 10000200.nand: NAND_CMD_GET_FEATURES =3D 0x00
[    0.569998] bcm6368_nand 10000200.nand: ll_op cmd 0x10000
[    0.575653] bcm6368_nand 10000200.nand: NAND_CMD_GET_FEATURES =3D 0x00
[    0.582246] bcm6368_nand 10000200.nand: ll_op cmd 0x80010000
[    0.588067] bcm6368_nand 10000200.nand: NAND_CMD_GET_FEATURES =3D 0x00
[    0.594657] nand: nand_get_features: addr=3Da0 subfeature_param=3D[00
00 00 00] -> 0
[    0.602341] macronix_nand_block_protection_support:
ONFI_FEATURE_ADDR_MXIC_PROTECTION=3D0
[    0.610548] macronix_nand_block_protection_support: !=3D
MXIC_BLOCK_PROTECTION_ALL_LOCK
[    0.624760] Bad block table not found for chip 0
[    0.635542] Bad block table not found for chip 0
[    0.640270] Scanning device for bad blocks

I don't know how to tell if get_features / set_features is really supported=
...

> - what is the state of the locking configuration in the chip when you
>   boot?

Unlocked, I guess...
How can I check that?

> - is there anything that locks the device by calling mxic_nand_lock() ?
> - finding no bbt is one thing, hanging is another, where is it hanging
>   exactly? (offset in nand/ and line in the code)

I've got no idea...

>
> >
> > >
> > > Otherwise, why would you disable the block protection? What does it
> > > mean exactly? I'm not in favor of a Macronix-specific property here.
> > >
> > > Thanks,
> > > Miqu=C3=A8l
> >
> > --
> > =C3=81lvaro
>
>
> Thanks,
> Miqu=C3=A8l