哇酷®开发者社区(WhyCan® Forum)

参照 orangepi pc plus 在设备树中添加了设备信息：
&mmc2 {
pinctrl-names = "default";
pinctrl-0 = <&mmc2_8bit_pins>;
vmmc-supply = <&reg_vcc3v3>;
bus-width = <8>;
non-removable;
cap-mmc-hw-reset;
status = "okay";
};

&mmc2_8bit_pins {
/ Increase drive strength for DDR modes /
allwinner,drive = <SUN4I_PINCTRL_40_MA>;
/ eMMC is missing pull-ups /
allwinner,pull = <SUN4I_PINCTRL_PULL_UP>;
};

启动log:
[ 1.028147] sunxi-mmc 1c11000.mmc: smc 1 err, cmd 8, RTO !!
[ 1.065805] sunxi-mmc 1c11000.mmc: smc 1 err, cmd 55, RTO !!
[ 1.072411] sunxi-mmc 1c11000.mmc: smc 1 err, cmd 55, RTO !!
[ 1.078901] sunxi-mmc 1c11000.mmc: smc 1 err, cmd 55, RTO !!
[ 1.085414] sunxi-mmc 1c11000.mmc: smc 1 err, cmd 55, RTO !!
[ 1.097286] sunxi-mmc 1c11000.mmc: smc 1 err, cmd 1, RTO !!

这会是什么问题？
可以从sd卡启动，说明mmc驱动没有问题，只需要在设备树中添加设备信息就行了。