[...]
>> > Actually the sdhci-of-esdhc driver would set host->ocr_mask when it
>> probes.
>> > mmc_of_parse_voltage(np, &host->ocr_mask);
>>
>> Okay, got it - thanks!
>>
>> So I tried to understand when the voltage-range binding should be used,
>> but the DT documentation is quite poor for it.
>>
>> Anyway, I assumes the binding is there to describe internal HW
>> characteristics of the what regulator levels the mmc controller can
>> support. And the regulator levels are for the power to the card, *not*
>> for the IO voltage.
>>
>> So, is this according to what you expects as well, especially since you
>> were aiming to fix something for the IO voltage in patch1?
>>
>> >
>> > But the "&" operation will make host->ocr_mask to have no use for other
>> voltage supporting.
>> > I think using "|" instead or just assigning host->ocr_mask to ocr_avail
>> should be ok.
>> > If so, there is no need to add this quirk.
>>
>> This is kind of a policy change for how to treat the configuration from
>> DT. I have cc:ed Haijun Zhang, which invented the binding to see if we
>> can get some feeback from him.
>>
>> The commit is: 6e9e318b304fd7373a0754805a76a02ddbc69a41 ("mmc: core:
>> parse voltage from device-tree")
>
> Haijun Zhang had left his job. And I have worked instead of him recently.
> I have new find about this.
>
> commit c0b887b66c95fe5abaac071b8332b8c21113d84b
> Author: Haijun Zhang <Haijun.Zhang@xxxxxxxxxxxxx>
> Date: Mon Aug 26 09:19:23 2013 +0800
>
> mmc: sdhci: get voltage from sdhc host
>
> We use host->ocr_mask to hold the voltage get from device-tree
> node, In case host->ocr_mask was available, we use host->ocr_mask
> as the final available voltage can be used by MMC/SD/SDIO card.
>
> Signed-off-by: Haijun Zhang <haijun.zhang@xxxxxxxxxxxxx>
> Reviewed-by: Anton Vorontsov <anton@xxxxxxxxxx>
> Signed-off-by: Chris Ball <cjb@xxxxxxxxxx>
>
> This was change by commit 3a48edc4bd68f841c07c7bc86358d2f02133f247.
> But I didn’t see the reason.
Oh, that's unfortunate. I think it shouldn't have done that.
>
>>
>> >
>> >>
>> >> Looking a bit further up in the code in sdhci_add_host(), you will
>> >> find that the ocr_avail mask is created by calling
>> >> mmc_regulator_get_supply() (and not mmc_of_parse() as told you before).
>> >> If there are external regulators, the ocr_avail mask will then
>> >> override the values from SDHCI's caps register.
>> >
>> > But there is no external regulator on boards that using eSDHC...
>> >
>>
>> Quoted from your response in patch1:
>> "Although the controller only supports 1.8v, the hardware circuit has a
>> level translator for supporting 3.3v".
>>
>> Again, that seems to concern the IO voltage, but if not - could it be
>> modelled as regulator and thus used to fetch the ocr mask from?
>>
>> It's quite common that we use GPIO regulators in the mmc subsystem for
>> this matter.
>>
> I am afraid not.
> Such as, some boards only support 1.8v, but we used adapter card that makes sd work on 3.3v power voltage and 3.3v IO voltage.
> And some boards may be integrated the level translator on the board to make sd card work on 3.3v power and 3.3v IO voltage.
>
>
I believe am starting to understand the problem now. You are likely
suffering from the change in 3a48edc4bd68f841c07c7bc86358d2f02133f247.
I will cook a patch for you that you can test.
Kind regards
Uffe
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