Re: [PATCH 2/2] ARM: dts: imx6: pfla02: Fix SD card reboot problem

[Andrej Picej <andrej.picej@norik.com>]

On 5. 07. 23 10:40, Andrej Picej wrote:
> 
> 
> On 5. 07. 23 10:30, Ahmad Fatoum wrote:
>> On 05.07.23 10:28, Andrej Picej wrote:
>>> Hi Marco,
>>>
>>> On 4. 07. 23 10:17, Marco Felsch wrote:
>>>> On 23-07-04, Andrej Picej wrote:
>>>>> If regulator is not marked as always-on the regulator gets disabled on
>>>>> reboot breaking the next boot.
>>>>>
>>>>> Signed-off-by: Andrej Picej <andrej.picej@norik.com>
>>>>> ---
>>>>>    arch/arm/boot/dts/imx6qdl-phytec-pfla02.dtsi | 1 +
>>>>>    1 file changed, 1 insertion(+)
>>>>>
>>>>> diff --git a/arch/arm/boot/dts/imx6qdl-phytec-pfla02.dtsi 
>>>>> b/arch/arm/boot/dts/imx6qdl-phytec-pfla02.dtsi
>>>>> index 80adb2a02cc9..25d6a036d5b8 100644
>>>>> --- a/arch/arm/boot/dts/imx6qdl-phytec-pfla02.dtsi
>>>>> +++ b/arch/arm/boot/dts/imx6qdl-phytec-pfla02.dtsi
>>>>> @@ -192,6 +192,7 @@ vdd_3v3_pmic_io_reg: ldo6 {
>>>>>                vdd_sd0_reg: ldo9 {
>>>>>                    regulator-min-microvolt = <3300000>;
>>>>>                    regulator-max-microvolt = <3300000>;
>>>>> +                regulator-always-on;
>>>>
>>>> I think this is the supply for the sd-card, so you can make use of
>>>> 'vmmc-supply'.
>>>
>>> This is already the case:
>>>
>>>> &usdhc3 {
>>>>      pinctrl-names = "default";
>>>>      pinctrl-0 = <&pinctrl_usdhc3
>>>>               &pinctrl_usdhc3_cdwp>;
>>>>      cd-gpios = <&gpio1 27 GPIO_ACTIVE_LOW>;
>>>>      wp-gpios = <&gpio1 29 GPIO_ACTIVE_HIGH>;
>>>>      vmmc-supply = <&vdd_sd0_reg>;
>>>>      status = "disabled";
>>>> };
>>>
>>> I think the main reason for a failed boot is that the PMIC doesn't 
>>> get reset and that the bootloader doesn't specifically enable the SD 
>>> card regulator.
>>>
>>> Could this patch still be applied or should we put the fix in reset 
>>> routine/bootloader?
>>
>> Is SD-Card not main boot medium? From your description, I thought BootROM
>> will fail to boot before bootloader has a chance to do anything about it.
>>
> 
> Yes sorry, you are absolutly right, the BootROM fails. It confused me 
> because I could see the booloader booting, but it was from one of the 
> fallback mediums. So I guess fixing the bootloader is not really an option.
> Sorry for the confusion.
> 

Ok, the main problem is well known, that's why PHYTEC disables the imx 
watchdog and uses a PMIC one for the reboot handler. This one resets the 
board completely. The SD card regulator problem is really just the 
manifestation of that bug. Unfortunately I didn't noticed that. :(

I will create a v2 with a proper fix, where imx watchdog gets disabled.

Thanks for your help,
Andrej


> 
>>>
>>> Best regards,
>>> Andrej
>>>
>>>>
>>>> Regards,
>>>>     Marco
>>>>
>>>>>                };
>>>>>                  vdd_sd1_reg: ldo10 {
>>>>> -- 
>>>>> 2.25.1
>>>>>
>>>>>
>>>>>
>>>
>>>
>>