Odroid-C1 regression with commit 4bc31edebde5 ("mmc: core: Set HS clock speed before sending HS CMD13")

[Linux regression tracking (Thorsten Leemhuis)]

Hi, Thorsten here, the Linux kernel's regression tracker. Top-posting
for once, to make this easily accessible to everyone.

I still have this regression (caused by a commit from Brian, applied by
Ulf) on my list of tracked issues. Was there any progress to finally get
this fixed[1]? Doesn't look like it from here, but I might have easily
missed something, that's why I'm asking.

[1] this patch from Ziyang Huang afaics was supposed to help, but it
went nowhere afaics
https://lore.kernel.org/linux-amlogic/TYZPR01MB5556B56D834E02F41C44D81DC95FA@TYZPR01MB5556.apcprd01.prod.exchangelabs.com/

Or does anybody stop caring?

Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)
--
Everything you wanna know about Linux kernel regression tracking:
https://linux-regtracking.leemhuis.info/about/#tldr
If I did something stupid, please tell me, as explained on that page.

#regzbot poke

On 20.06.23 11:53, Ulf Hansson wrote:
> On Mon, 19 Jun 2023 at 21:54, Martin Blumenstingl
> <martin.blumenstingl at googlemail.com> wrote:
>>
>> On Wed, Jun 14, 2023 at 5:49 PM Ulf Hansson <ulf.hansson at 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 ;-)
> 
> Sometimes a well written commit message actually helps. :-)
> 
>> 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)
>
> Great news!
> 
> I will continue to monitor the thread and defer to apply anything
> until you have given it your blessing, of course.
> 
> Kind regards
> Uffe