query kernel error

[jossvall]

I am working with a custom PCB for an omega2s +.
in the device there is an omega2s + a GPS and a modem and a 4 channel optocoupler to handle GPIO signals.

they have been in testing for about 2 months today in a normal check routine run logread "and I was surprised, the log was full with the following message

Thu Jul 15 16:28:32 2021 kern.warn kernel: [102649.066406] mtk-sd 10130000.sdhci: no support for card's volts
Thu Jul 15 16:28:32 2021 kern.err kernel: [102649.072469] mmc0: error -22 whilst initialising SDIO card
Thu Jul 15 16:28:32 2021 kern.warn kernel: [102649.079851] mtk-sd 10130000.sdhci: no support for card's volts
Thu Jul 15 16:28:32 2021 kern.err kernel: [102649.085953] mmc0: error -22 whilst initialising MMC card
Thu Jul 15 16:28:32 2021 kern.warn kernel: [102649.166957] mtk-sd 10130000.sdhci: no support for card's volts
Thu Jul 15 16:28:32 2021 kern.err kernel: [102649.173044] mmc0: error -22 whilst initialising SDIO card
Thu Jul 15 16:28:32 2021 kern.warn kernel: [102649.181002] mtk-sd 10130000.sdhci: no support for card's volts
Thu Jul 15 16:28:32 2021 kern.err kernel: [102649.187098] mmc0: error -22 whilst initialising MMC card
Thu Jul 15 16:28:33 2021 kern.warn kernel: [102649.267201] mtk-sd 10130000.sdhci: no support for card's volts
Thu Jul 15 16:28:33 2021 kern.err kernel: [102649.273270] mmc0: error -22 whilst initialising SDIO card
Thu Jul 15 16:28:33 2021 kern.warn kernel: [102649.281234] mtk-sd 10130000.sdhci: no support for card's volts
Thu Jul 15 16:28:33 2021 kern.err kernel: [102649.287316] mmc0: error -22 whilst initialising MMC card
Thu Jul 15 16:28:33 2021 kern.warn kernel: [102650.106696] mtk-sd 10130000.sdhci: no support for card's volts
Thu Jul 15 16:28:33 2021 kern.err kernel: [102650.112772] mmc0: error -22 whilst initialising SDIO card
Thu Jul 15 16:28:33 2021 kern.warn kernel: [102650.120103] mtk-sd 10130000.sdhci: no support for card's volts
Thu Jul 15 16:28:33 2021 kern.err kernel: [102650.126184] mmc0: error -22 whilst initialising MMC card
Thu Jul 15 16:28:34 2021 kern.warn kernel: [102650.206946] mtk-sd 10130000.sdhci: no support for card's volts
Thu Jul 15 16:28:34 2021 kern.err kernel: [102650.213015] mmc0: error -22 whilst initialising SDIO card
Thu Jul 15 16:28:34 2021 kern.warn kernel: [102650.221053] mtk-sd 10130000.sdhci: no support for card's volts
Thu Jul 15 16:28:34 2021 kern.err kernel: [102650.227140] mmc0: error -22 whilst initialising MMC card
Thu Jul 15 16:28:34 2021 kern.warn kernel: [102650.307188] mtk-sd 10130000.sdhci: no support for card's volts
Thu Jul 15 16:28:34 2021 kern.err kernel: [102650.313262] mmc0: error -22 whilst initialising SDIO card
Thu Jul 15 16:28:34 2021 kern.warn kernel: [102650.321487] mtk-sd 10130000.sdhci: no support for card's volts
Thu Jul 15 16:28:34 2021 kern.err kernel: [102650.327584] mmc0: error -22 whilst initialising MMC card
Thu Jul 15 16:28:34 2021 kern.warn kernel: [102651.146325] mtk-sd 10130000.sdhci: no support for card's volts
Thu Jul 15 16:28:34 2021 kern.err kernel: [102651.152392] mmc0: error -22 whilst initialising SDIO card
Thu Jul 15 16:28:34 2021 kern.warn kernel: [102651.159595] mtk-sd 10130000.sdhci: no support for card's volts
Thu Jul 15 16:28:34 2021 kern.err kernel: [102651.165680] mmc0: error -22 whilst initialising MMC card

the log size is 1020 KB and you just see that message over and over again. After a quick search in google, I saw several forums where they relate this error to the support for SD, but in my PCB it is not and using any of these pins, these pins are floating.

• Does anyone have any idea of ​​the reason for that error?
• should I use pullup / pulldown resistors on the SD lines?

NOTES:
Regardless of the error that the kernel is reporting, the omega2s + is working, all the programs that I compile to perform the tasks that are needed are also working well, I just want to make sure of the cause of the problem, since the device is in its final stage of tests and is about to go into production.

also restart the omega2s + but the kernel keeps generating the error message.

[JeffZhou]

Hi, if you don't need to use Micro SD Card .

1. As Onion Firmware's SD Card funtion will be actived when SD_CD PIN at High-level.When you keep using Onion Firmware,you can use pulldown resistor to set the SD_CD PIN to low-level.
2. You can set each SD Card PIN to GPIO Mode.

[crispyoz]

@jossvall I wonder if removing the mmc kernel module would solve this issue without the need to modify your hardware design this late in the game.