低温下，emmc数据读取错误：mmcblk1: error -84 transferring data, sector 290504, nr 168, cmd response 0x900, card

[xiaobakang]

问题产品使用的imx6ull系列芯片，目前存在的问题是：低温下（大约超过-10℃）emmc读取错误，常温下也会偶尔出现同样问题，但是概率极低。附件是截取的2款emmc上电输出信息。

        目前试了4块电路板两款emmc芯片，都存在同样问题，排除了emmc不耐低温的可能性。以下下是emmc的设备树配置：

pinctrl_usdhc2_8bit: usdhc2grp_8bit {

fsl,pins = <

MX6UL_PAD_NAND_RE_B__USDHC2_CLK     0x10069

MX6UL_PAD_NAND_WE_B__USDHC2_CMD     0x17059

MX6UL_PAD_NAND_DATA00__USDHC2_DATA0 0x17059

MX6UL_PAD_NAND_DATA01__USDHC2_DATA1 0x17059

MX6UL_PAD_NAND_DATA02__USDHC2_DATA2 0x17059

MX6UL_PAD_NAND_DATA03__USDHC2_DATA3 0x17059

MX6UL_PAD_NAND_DATA04__USDHC2_DATA4 0x17059

MX6UL_PAD_NAND_DATA05__USDHC2_DATA5 0x17059

MX6UL_PAD_NAND_DATA06__USDHC2_DATA6 0x17059

MX6UL_PAD_NAND_DATA07__USDHC2_DATA7 0x17059

>;

};

pinctrl_usdhc2_8bit_100mhz: usdhc2grp_8bit_100mhz {

fsl,pins = <

MX6UL_PAD_NAND_RE_B__USDHC2_CLK     0x100b9

MX6UL_PAD_NAND_WE_B__USDHC2_CMD     0x170b9

MX6UL_PAD_NAND_DATA00__USDHC2_DATA0 0x170b9

MX6UL_PAD_NAND_DATA01__USDHC2_DATA1 0x170b9

MX6UL_PAD_NAND_DATA02__USDHC2_DATA2 0x170b9

MX6UL_PAD_NAND_DATA03__USDHC2_DATA3 0x170b9

MX6UL_PAD_NAND_DATA04__USDHC2_DATA4 0x170b9

MX6UL_PAD_NAND_DATA05__USDHC2_DATA5 0x170b9

MX6UL_PAD_NAND_DATA06__USDHC2_DATA6 0x170b9

MX6UL_PAD_NAND_DATA07__USDHC2_DATA7 0x170b9

>;

};

pinctrl_usdhc2_8bit_200mhz: usdhc2grp_8bit_200mhz {

fsl,pins = <

MX6UL_PAD_NAND_RE_B__USDHC2_CLK     0x100f9

MX6UL_PAD_NAND_WE_B__USDHC2_CMD     0x170f9

MX6UL_PAD_NAND_DATA00__USDHC2_DATA0 0x170f9

MX6UL_PAD_NAND_DATA01__USDHC2_DATA1 0x170f9

MX6UL_PAD_NAND_DATA02__USDHC2_DATA2 0x170f9

MX6UL_PAD_NAND_DATA03__USDHC2_DATA3 0x170f9

MX6UL_PAD_NAND_DATA04__USDHC2_DATA4 0x170f9

MX6UL_PAD_NAND_DATA05__USDHC2_DATA5 0x170f9

MX6UL_PAD_NAND_DATA06__USDHC2_DATA6 0x170f9

MX6UL_PAD_NAND_DATA07__USDHC2_DATA7 0x170f9

>;

};

&usdhc2 {   

pinctrl-names = "default","state_100mhz", "state_200mhz";

pinctrl-0 = <&pinctrl_usdhc2_8bit>;

        pinctrl-0 = <&pinctrl_usdhc2_8bit_100mhz>;

        pinctrl-0 = <&pinctrl_usdhc2_8bit_200mhz>;

        bus-width = <8>;

non-removable;

status = "okay";

};

[Rita_Wang]

For the others chips in your board also can work well at the low temperature, you need to check.