Re: [PATCH 3/3] arm64: dts: rockchip: fix RockPro64 sdmmc settingsãèææïéäçlinux-rockchip-bounces+shawn.lin=rock-chips.com@xxxxxxxxxxxxxxxxxxxäåã

[Jonas Karlman]

On 2019-10-04 16:20, Robin Murphy wrote:
> On 04/10/2019 04:39, Soeren Moch wrote:
>>
>> On 04.10.19 04:13, Shawn Lin wrote:
>>> On 2019/10/4 8:53, Soeren Moch wrote:
>>>>
>>>> On 04.10.19 02:01, Robin Murphy wrote:
>>>>> On 2019-10-03 10:50 pm, Soeren Moch wrote:
>>>>>> According to the RockPro64 schematic [1] the rk3399 sdmmc
>>>>>> controller is
>>>>>> connected to a microSD (TF card) slot, which cannot be switched to
>>>>>> 1.8V.
>>>>> Really? AFAICS the SDMMC0 wiring looks pretty much identical to the
>>>>> NanoPC-T4 schematic (it's the same reference design, after all), and I
>>>>> know that board can happily drive a UHS-I microSD card with 1.8v I/Os,
>>>>> because mine's doing so right now.
>>>>>
>>>>> Robin.
>>>> OK, the RockPro64 does not allow a card reset (power cycle) since
>>>> VCC3V0_SD is directly connected to VCC3V3_SYS (via R89555), the
>>>> SDMMC0_PWH_H signal is not connected. So the card fails to identify
>>>> itself after suspend or reboot when switched to 1.8V operation.
> Ah, thanks for clarifying - I did overlook the subtlety that U12 and 
> friends have "NC" as alternative part numbers, even though they aren't 
> actually marked as DNP. So it's still not so much "cannot be switched" 
> as "switching can lead to other problems".
>
>>> I believe we addressed this issue long time ago, please check:
>>>
>>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=6a11fc47f175c8d87018e89cb58e2d36c66534cb
>>>
>> Thanks for the pointer.
>> In this case I guess I should use following patch instead:
>>
>> --- rk3399-rockpro64.dts.bak ÂÂ 2019-10-03 22:14:00.067745799 +0200
>> +++ rk3399-rockpro64.dtsÂÂÂ 2019-10-04 00:02:50.047892366 +0200
>> @@ -619,6 +619,8 @@
>>  ÂÂÂÂ max-frequency = <150000000>;
>>  ÂÂÂÂ pinctrl-names = "default";
>>  ÂÂÂÂ pinctrl-0 = <&sdmmc_clk &sdmmc_cmd &sdmmc_bus4>;
>> +ÂÂÂ sd-uhs-sdr104;
>> +ÂÂÂ vqmmc-supply = <&vcc_sdio>;
>>  ÂÂÂÂ status = "okay";
>>  Â};
>>   
>> When I do so, the sd card is detected as SDR104, but a reboot hangs:
>>
>> Boot1: 2018-06-26, version: 1.14
>> CPUId = 0x0
>> ChipType = 0x10, 286
>> Spi_ChipId = c84018
>> no find rkpartition
>> SpiBootInit:ffffffff
>> mmc: ERROR: SDHCI ERR:cmd:0x102,stat:0x18000
>> mmc: ERROR: Card did not respond to voltage select!
>> emmc reinit
>> mmc: ERROR: SDHCI ERR:cmd:0x102,stat:0x18000
>> mmc: ERROR: Card did not respond to voltage select!
>> emmc reinit
>> mmc: ERROR: SDHCI ERR:cmd:0x102,stat:0x18000
>> mmc: ERROR: Card did not respond to voltage select!
>> SdmmcInit=2 1
>> mmc0:cmd5,32
>> mmc0:cmd7,32
>> mmc0:cmd5,32
>> mmc0:cmd7,32
>> mmc0:cmd5,32
>> mmc0:cmd7,32
>> SdmmcInit=0 1
>>
>> So I guess I should use a different miniloader for this reboot to work!?
>> Or what else could be wrong here?
> Hmm, I guess this is "the Tinkerboard problem" again - the patch above 
> would be OK if we could get as far as the kernel, but can't help if the 
> offending card is itself the boot medium. There was a proposal here:
>
> https://patchwork.kernel.org/patch/10817217/
>
> although I'm not sure what if any progress has been made since then.

Correct, I never got around to complete testing on other devices.
Maybe someone more familiar with mmc subsystem can pick that up if it now turns out other devices show the same/similar issue?

fwiw the "mmc: core: set initial signal voltage on power off" rfc/patch have been used in LibreELEC rockchip builds for well over a year now.

Regards,
Jonas

>
> Robin.
>