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References: <d4338bd5-125c-a9e7-cb46-6f5e1da05cfa@sberdevices.ru>
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From:   Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Date:   Wed, 22 Mar 2023 21:10:12 +0100
Message-ID: <CAFBinCB3yuyNJD=7UJ7jzf45Masms_PD4sm42YNjO8M4cr+4wg@mail.gmail.com>
Subject: Re: [PATCH v1] mtd: rawnand: meson: fix bitmask for length in command word
To:     Arseniy Krasnov <avkrasnov@sberdevices.ru>
Cc:     Liang Yang <liang.yang@amlogic.com>,
        Miquel Raynal <miquel.raynal@bootlin.com>,
        Richard Weinberger <richard@nod.at>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Neil Armstrong <neil.armstrong@linaro.org>,
        Kevin Hilman <khilman@baylibre.com>,
        Jerome Brunet <jbrunet@baylibre.com>,
        Jianxin Pan <jianxin.pan@amlogic.com>,
        Yixun Lan <yixun.lan@amlogic.com>,
        linux-mtd@lists.infradead.org,
        linux-arm-kernel@lists.infradead.org,
        linux-amlogic@lists.infradead.org, linux-kernel@vger.kernel.org,
        kernel@sberdevices.ru, oxffffaa@gmail.com
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Hello Arseniy,

thank you for submitting this fix!

On Wed, Mar 22, 2023 at 7:45=E2=80=AFPM Arseniy Krasnov
<avkrasnov@sberdevices.ru> wrote:
>
> Valid mask is 0x3FFF, without this patch the following problems were
> found:
>
> 1) [    0.938914] Could not find a valid ONFI parameter page, trying
>                   bit-wise majority to recover it
>    [    0.947384] ONFI parameter recovery failed, aborting
>
> 2) Read with disabled ECC mode was broken.
>
> Fixes: 8fae856c5350 ("mtd: rawnand: meson: add support for Amlogic NAND f=
lash controller")
> Signed-off-by: Arseniy Krasnov <AVKrasnov@sberdevices.ru>
This matches what I can see in the old vendor driver, so:
Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>

[...]
> -               cmd =3D (len & GENMASK(5, 0)) | scrambler | DMA_DIR(dir);
> +               cmd =3D (len & GENMASK(13, 0)) | scrambler | DMA_DIR(dir)=
;
My understanding of the vendor driver is that this "len" is only used
for "raw" access (my own words: any access that doesn't use the HW ECC
engine).
As a future improvement (no need to update re-send this patch) it
would be great to have a #define with a meaningful name for
"GENMASK(13, 0)" (maybe something like NFC_CMD_RAW_LENGTH) as it's
used in multiple places now


Best regards,
Martin