On 22-10-24, Peng Fan (OSS) wrote:
> From: Peng Fan <peng.fan@xxxxxxx>
>
> Some SD Card controller and power circuitry has increased capacitance,
> so the usual toggling of regulator to power the card off and on
> is insufficient.
>
> According to SD spec, for sd card power reset operation, the sd card
> supply voltage needs to be lower than 0.5v and keep over 1ms, otherwise,
> next time power back the sd card supply voltage to 3.3v, sd card can't
> support SD3.0 mode again.
>
> This patch add the off-on-delay-us, make sure the sd power reset behavior
> is align with the specification. Without this patch, when do quick system
> suspend/resume test, some sd card can't work at SD3.0 mode after system
> resume back.
>
> Signed-off-by: Peng Fan <peng.fan@xxxxxxx>
> ---
> arch/arm64/boot/dts/freescale/imx8mn-evk.dtsi | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/arm64/boot/dts/freescale/imx8mn-evk.dtsi b/arch/arm64/boot/dts/freescale/imx8mn-evk.dtsi
> index 261c36540079..2b4395854283 100644
> --- a/arch/arm64/boot/dts/freescale/imx8mn-evk.dtsi
> +++ b/arch/arm64/boot/dts/freescale/imx8mn-evk.dtsi
> @@ -36,6 +36,7 @@ reg_usdhc2_vmmc: regulator-usdhc2 {
> regulator-min-microvolt = <3300000>;
> regulator-max-microvolt = <3300000>;
> gpio = <&gpio2 19 GPIO_ACTIVE_HIGH>;
> + off-on-delay-us = <12000>;
All others are using 20000us, did you changed the HW?
Regards,
Marco
> enable-active-high;
> };
>
> --
> 2.37.1
>
>
>
