Hi,
I'm trying to use i.MX8MQ-EVK board MMC1(usdhc2) in SDIO3.0 SDR104 mode, to work with WLAN card.
working with yocto release imx-linux-honister with kernel version v5.15.5.
Facing issues with operating in both SDIO2.0 50MHz & SDIO3.0 SDR104 200MHz clock modes
Listing below the tests I have tried.
1. Default code from imx-linux-honister release without any change
Result: WLAN Card is detected as SDR104 UHS card. But SDIO bus error (-84) is seen
Both SDIO2.0 HS 50MHz mode & SDIO 3.0 UHS 200MHz mode are Not Working
2. Modify imx8mq-evk.dts to update “pinctrl_usdhc2_200mhz” to support Max Slewrate
Result: WLAN Card is detected as SDR104 UHS card. But SDIO bus error (-84) & timeout (-110) is seen
Both SDIO2.0 HS 50MHz mode & SDIO 3.0 UHS 200MHz mode are Not Working
3. Integrate the patch “L3.10.17_1.0.0_MX6SL_SDHC3_1v8_kernel.patch” suggested in NXP forum
Result: WLAN Card is detected as SDR104 UHS card. But SDIO timeout (-110) is seen
SDIO2.0 HS mode with 50MHz clock is Working Successfully.
Figured out that disabling below code helps to successfully run SDIO2.0 50MHz mode.
imx_data->pins_100mhz = pinctrl_lookup_state(imx_data->pinctrl, ESDHC_PINCTRL_STATE_100MHZ);
imx_data->pins_200mhz = pinctrl_lookup_state(imx_data->pinctrl, ESDHC_PINCTRL_STATE_200MHZ);
But couldn't figure out how to successfully run SDIO3.0 200MHz mode.
Tested the same WLAN card with kernel v5.15.5 in i.MX6SLL-EVK, both SDIO2.0 50MHz & SDIO3.0 200MHZ are working correctly.
The only change needed was to edit pinctrl_usdhc3_200mhz in "imx6sll-eck.dts" to support Max slewrate.
Attaching here the DTB & SDIO patches applied to imx-linux-honister code and WLAN card SDIO logs.
Kindly help me figure out how to resolve this problem
Thanks.
Regards,
Pandi Vijayaraj
