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References: <20240221-fix-sh-mmcif-v2-0-5e521eb25ae4@linaro.org> <20240221-fix-sh-mmcif-v2-2-5e521eb25ae4@linaro.org>
In-Reply-To: <20240221-fix-sh-mmcif-v2-2-5e521eb25ae4@linaro.org>
From: Geert Uytterhoeven <geert@linux-m68k.org>
Date: Thu, 22 Feb 2024 10:20:22 +0100
Message-ID: <CAMuHMdW=PogDu8RAKvBw6wY280zg53-aNypdmBQDgbanOXQFSA@mail.gmail.com>
Subject: Re: [PATCH v2 2/2] mmc: sh_mmcif: Advance sg_miter before reading blocks
To: Linus Walleij <linus.walleij@linaro.org>
Cc: Ulf Hansson <ulf.hansson@linaro.org>, linux-mmc@vger.kernel.org, 
	linux-kernel@vger.kernel.org
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On Wed, Feb 21, 2024 at 10:23=E2=80=AFPM Linus Walleij <linus.walleij@linar=
o.org> wrote:
> The introduction of sg_miter was a bit sloppy as it didn't
> exactly mimic the semantics of the old code on multiblock reads
> and writes: these like you to:
>
> - Advance to the first sglist entry *before* starting to read
>   any blocks from the card.
>
> - Advance and check availability of the next entry *right after*
>   processing one block.
>
> Not checking if we have more sglist entries right after
> reading a block will lead to this not being checked until we
> return to the callback to read out more blocks, i.e. until the
> next interrupt arrives. Since the last block is the last one
> (no more data will arrive) there will not be a next interrupt,
> and we will be waiting forever resulting in a timeout for
> command 18 when reading multiple blocks.
>
> The same bug was fixed also in the writing of multiple blocks.
>
> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
> Fixes: 27b57277d9ba ("mmc: sh_mmcif: Use sg_miter for PIO")
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Thanks, eMMC works again (tested on APE6EVM and KZM9-GT-Dual).
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>

Gr{oetje,eeting}s,

                        Geert

--=20
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k=
org

In personal conversations with technical people, I call myself a hacker. Bu=
t
when I'm talking to journalists I just say "programmer" or something like t=
hat.
                                -- Linus Torvalds