topic Re: SDR104 support in USDHC2 in i.MX Processors

SDR104 support in USDHC2

yashavanthashet — Fri, 02 Nov 2018 14:10:54 GMT

Hi,

We are using i.MX8M custom board with Linux4.9.51_ga release.

We are facing issue with UHS sd cards.

Even after removing "sd-uhs-sdr104" property from "&usdhc2" node in dts, card will detect with UHS SDR104 mode and fails. Kindly let us know where exactly we needs to change in order to make card detect only n DDR50 mode.

Thanks in advance.

Regards,

Yashavantha

Re: SDR104 support in USDHC2

yashavanthashet — Tue, 06 Nov 2018 12:10:03 GMT

Hi,

Any answer?

Thanks and Regardsm

Yashavantha

Re: SDR104 support in USDHC2

igorpadykov — Tue, 06 Nov 2018 23:21:04 GMT

Hi Yashavantha

"sd-uhs-sdr104" property is not supported by i.MX8M usdhc driver

fsl-imx8mq.dtsi\freescale\dts\boot\arm64\arch - linux-imx - i.MX Linux kernel

one can try "no-1-8-v", like:

&usdhc { ..
no-1-8-v;
status = "okay";

Best regards
igor
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Re: SDR104 support in USDHC2

yashavanthashet — Wed, 07 Nov 2018 04:55:43 GMT

Hi Igor,

What do u mean by ""sd-uhs-sdr104" property is not supported by i.MX8M"? Can't we test ultra high speed cards in i.MX8M board?

Then what is the maximum SD speed supported?

Thanks and Regards,

Yashavantha

Re: SDR104 support in USDHC2

igorpadykov — Wed, 07 Nov 2018 05:18:17 GMT

"sd-uhs-sdr104" property is optional and not supported by i.MX8M esdhc driver

linux/drivers/mmc/host/sdhci-esdhc-imx.c

sdhci-esdhc-imx.c\host\mmc\drivers - linux-imx - i.MX Linux kernel

What is supported is documented on

linux/Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.txt

fsl-imx-esdhc.txt\mmc\bindings\devicetree\Documentation - linux-imx - i.MX Linux kernel

Supported speeds are described in sect.10.3.1.1 Features i.MX8M Reference Manual.

Best regards
igor