Hi all, I am using linux kernel 3.10.17. I have interfaced wifi module from TI to sdio interface. I am getting following error in kernel logs mmc0: Switching to 3.3V signaling voltage failed i have done following configuration in device tree. reg_3p3v: 3p3v { compatible = "regulator-fixed"; regulator-name = "3P3V"; regulator-min-microvolt = <3300000>; regulator-max-microvolt = <3300000>; regulator-always-on; }; wilink_wl_en: tiwi_wlan { compatible = "regulator-fixed"; regulator-name = "wilink_wl_en"; regulator-min-microvolt = <1800000>; regulator-max-microvolt = <1800000>; gpio = <&gpio1 12 0>; startup-delay-us = <70000>; enable-active-high; }; and for usdhc1, &usdhc1 { pinctrl-names = "default"; pinctrl-0 = <&pinctrl_usdhc1_1>; bus-width = <4>; non-removable; vmmc-supply = <®_3p3v>; vqmmc-supply = <&wilink_wl_en>; ocr-limit = <0x80>; power-off-card; keep-power-in-suspend; status = "okay"; }; What can be the reason of error mmc0: Switching to 3.3V signaling voltage failed? -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html