[PATCH 13/18] rockchip: rk3588: fix non-working SD controller if booting from other media

[Dragan Simic]

On 2024-01-26 14:46, Quentin Schulz wrote:
> On 1/26/24 12:33, Dragan Simic wrote:
>> On 2024-01-26 12:29, Quentin Schulz wrote:
>>> On 1/26/24 12:24, Dragan Simic wrote:
>>>> On 2024-01-26 12:09, Quentin Schulz wrote:
>>>>> On 1/26/24 12:04, Dragan Simic wrote:
>>>>>> On 2024-01-26 11:37, Quentin Schulz wrote:
>>>>>>> On 1/26/24 03:57, Kever Yang wrote:
>>>>>>>> On 2024/1/25 19:02, Quentin Schulz wrote:
>>>>>>>>> We don't have a dedicated CD pin for the SD card connector.
>>>>>>>>> https://www.digikey.com/en/products/detail/molex/0472192001/3044807
>>>>>>>>> is the SD card connector we use.
>>>>>>>> 
>>>>>>>> Thanks for your information, but I think you are using the wrong
>>>>>>>> microSD connector for rk3588 and maybe also for other rockchip 
>>>>>>>> SoCs.
>>>>>>>> Here are four microSD card connector from the web you provide, 
>>>>>>>> all
>>>>>>>> of
>>>>>>>> them have card detect signal available for pcb:
>>>>>>>> https://www.digikey.com/en/product-highlight/m/molex-connector/sd-memory-card-connectors
>>>>>>> 
>>>>>>> None of those fit our requirements. We need a safe system that
>>>>>>> doesn't
>>>>>>> break because of vibrations or shocks. Push-pull connectors are 
>>>>>>> out
>>>>>>> of
>>>>>>> question for our design. We have had issues with our Q7 devkit 
>>>>>>> with
>>>>>>> push-pull connector with SD cards slightly smaller or inserted
>>>>>>> somewhat the wrong way. I can recall also countless of 
>>>>>>> discussions in
>>>>>>> the early days of the Raspberry Pis where there were a lot of 
>>>>>>> issues
>>>>>>> related to SD cards.
>>>>>>> 
>>>>>>> This is basically the mechanism we are using
>>>>>>> https://media.distrelec.com/Web/WebShopImages/landscape_large/4-/01/Molex-500901-0801-30161714-01.jpg
>>>>>> 
>>>>>> Please, allow me to interject...  I'm really curious why don't you
>>>>>> use eMMC chips instead of microSD cards?  I mean, if the 
>>>>>> reliability
>>>>>> is of utmost importance, I wouldn't even consider microSD cards, 
>>>>>> not
>>>>>> even the high-endurance variants.
>>>>> 
>>>>> We have both :)
>>>> 
>>>> Ah, I see. :)  Perhaps my question wasn't precise enough;  actually,
>>>> now I'd like to know what do you use as the primary storage for the
>>>> operating system installation -- eMMC chip or microSD cards?  Is the
>>>> eMMC chip soldered?  I'm just curious. :)
>>>> 
>>> Soldered eMMC is the primary (expected) storage. If both eMMC and SD
>>> card are inserted and properly flashed, it'll boot from eMMC except 
>>> if
>>> the BIOS button is pressed, in which case SD card will be selected
>>> instead. If SD card is missing/improperly flashed, it'll boot into 
>>> USB
>>> flashing mode (rkdeveloptool/rockusb) if the BIOS button is pressed
>>> (similar to when no storage media is properly flashed).
>> 
>> Thanks for the clarification.  Just one more question, please:  is the
>> BIOS button handled in software (i.e. in U-Boot), or does it disable 
>> the
>> eMMC chip by shorting its clock or a data line to ground?
> 
> None of those options :)
> 
> On RK3588, the boot media selection and order is done via the channel
> 0 of the SARADC. So a specific voltage is provided to boot from eMMC
> or from SD card.

Ah, it's nice to see that RK3588 feature actually used.  Thanks for
the clarification!