[i.MX8Mmini] Could you please advise how to change the SDIO speed?

[kazuyayamauchi]

We are running on i.MX8Mmini-EVK using LF_v6.6.52-2.2.0_images_IMX8MMEVK.
In this environment, we are connecting the WLAN module via SDIO.

We are experiencing issues with SDIO communication failing at high and low temperature environment.
To avoid this issue, we want to change the SDIO speed from

"SDR104 mode (208 MHz) (1.8V)"
to

"DDR50 mode (50 MHz) (1.8V)" or "HS mode (25MHz) (3.3V)".

Could you please advise how to change the SDIO speed?

Best Regards,

[kazuyayamauchi]

Dear joanxie-san,

Sorry for our reply overdue.

We were able to change the SDIO speed with your advice.
We were able to confirm the expected behavior.

We appreciate your support.

Best Regards,

[kazuyayamauchi]

Dear joanxie-san,

Thank you for your support.

We will try the steps your advised.

Best Regards,

[joanxie]

glad to hear this, this thread will be closed soon, any further questions, pls contact us again

[joanxie · Accepted solution]

I don't know why the reply was gone, I post again

 you can refer to this try to add  sd-uhs-sdr50 in the dts file and set the max-frequency in the dts

https://github.com/nxp-imx/linux-imx/blob/b586a521770e508d1d440ccb085c7696b9d6d387/Documentation/dev...

also can try to set sdhci-caps-mask = <0x00000003 0x00000000>; in the dts to force the mode to the DDR50