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From: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
To: Ulf Hansson <ulf.hansson@linaro.org>
Cc: linux-amlogic@lists.infradead.org, linux-mmc@vger.kernel.org,
	Brian Norris <briannorris@chromium.org>,
	Shawn Lin <shawn.lin@rock-chips.com>, Luca Weiss <luca@z3ntu.xyz>
Subject: Re: Odroid-C1 regression with commit 4bc31edebde5 ("mmc: core: Set HS clock speed before sending HS CMD13")
Date: Mon, 19 Jun 2023 21:54:26 +0200	[thread overview]
Message-ID: <CAFBinCCnB=po9x6tsxCzRM99ZqgV9=5jBxS9LaoJqLPGZYSH6g@mail.gmail.com> (raw)
In-Reply-To: <CAPDyKFpS-UwiaRPMqSpX0mNPrS5p=yJzu3g0=pGyCkWHSYyqWg@mail.gmail.com>

Hi Ulf,

On Wed, Jun 14, 2023 at 5:49 PM Ulf Hansson <ulf.hansson@linaro.org> wrote:
[...]
> > Full register dump:
> > # cat /sys/kernel/debug/regmap/c1108e00.mmc/registers
> > 00: 00000900
> > 04: 0000004d
> > 08: e7ffe002
> > 0c: 02f0003f
> > 10: 0003f009
> > 14: 03b81c00
> > 18: 2c43bcf0
> > 1c: e0000150
> > 20: 00000000
> > 24: 00003067
> > 28: 00000000
> > 2c: 00000000
> > 30: 00000000
> > 34: 00fe0cff
> > 38: 0000100b
> >
> > In case you are curious, the driver is: drivers/mmc/host/meson-mx-sdhc-mmc.c
>
> Thanks for sharing this data!
>
> I assume the above registers indicate that we have sent the command
> and are now waiting for an IRQ for a response/error, but we never
> receive one.
>
> To really figure out what is going on, I think we need to do some
> additional low level debugging/testing.
>
> I was looking at the commit message from e4bf1b0970ef ("mmc: host:
> meson-mx-sdhc: new driver for the Amlogic Meson SDHC host"), which
> indicates that the clock management is quite limited for this HW. For
> example, the 51000000Hz isn't one of the supported frequencies. Could
> that be the reason for the problem? Perhaps if we play with changing
> the frequency to something that is considered supported - then can we
> make this work?
You seem to be more familiar with this Amlogic MMC controller than I am ;-)
Today I finally had some time for testing and when I started Ziyang
Huang provided a patch [0] (admittedly: I think it needs to be
improved, but finally we know that it's a MMC controller driver
limitation and not an MMC core bug)


Best regards,
Martin


[0] https://lore.kernel.org/linux-amlogic/TYZPR01MB5556B56D834E02F41C44D81DC95FA@TYZPR01MB5556.apcprd01.prod.exchangelabs.com/

  reply	other threads:[~2023-06-19 19:54 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-04-10 23:13 Odroid-C1 regression with commit 4bc31edebde5 ("mmc: core: Set HS clock speed before sending HS CMD13") Martin Blumenstingl
2023-04-13 14:00 ` Linux regression tracking (Thorsten Leemhuis)
2023-05-08 20:12 ` Martin Blumenstingl
2023-05-10 14:20 ` Ulf Hansson
2023-05-10 20:54   ` Martin Blumenstingl
2023-05-11 10:42     ` Ulf Hansson
2023-05-14 20:42       ` Martin Blumenstingl
2023-05-15  9:43         ` Ulf Hansson
2023-05-16 20:45           ` Martin Blumenstingl
2023-06-02 13:17             ` Linux regression tracking (Thorsten Leemhuis)
2023-06-05 21:01               ` Martin Blumenstingl
2023-06-14 15:49             ` Ulf Hansson
2023-06-19 19:54               ` Martin Blumenstingl [this message]
2023-06-20  9:53                 ` Ulf Hansson
2023-08-29  9:59                   ` Linux regression tracking (Thorsten Leemhuis)
2023-09-11  8:48                     ` Thorsten Leemhuis

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