i.MX ProcessorsのトピックRe: imx6ul tf card

imx6ul tf card

songyonglai — Mon, 02 Nov 2020 07:11:02 GMT

Hi Igorpadykov: On my board, I use the usdhc2 to connect a emmc to boot from, and use the usdhc1 to connect a SD(TF) card, when I plug a TF card, the kernel can detect it ,but can not attach successfully. I debug the kernel and find a error in sdhci_cmd_irq() ,the error is SDHCI_INT_DATA_END_BIT(this is defined in file sdhci.h of kernel file). So I don't know why this error occurs. (I use the imx6ul-14*14-evk.dts). Igorpadykov ,would you help me and give me some suggestions, thanks very much .

Re: imx6ul tf card

igorpadykov — Mon, 02 Nov 2020 09:09:16 GMT

Hi songyonglai

such error was reported on other forums like https://forums.developer.nvidia.com/t/debugging-sd-uhs-cards-on-the-tx2/67641/3

and seems it is related to signal integrity, so one can try solutions for improving signal quality suggested on

https://community.nxp.com/t5/i-MX-Processors/eMMC-8GB-to-4GB-crash-on-linux-yocto-boot/m-p/373231

Best regards
igor

Re: imx6ul tf card

songyonglai — Tue, 03 Nov 2020 02:16:21 GMT

Hi Igorpadykov:

Thanks for your reply. It seems that my problem is not same with the one you discussed above. I think if SD1 cmd and clock pinmux value were not set correct. In dts file imx6ul-14*14-evk.dts, I usethe pinmuxs as follows referenced from demo board:

pinctrl_usdhc1:usdhc1grp{

MX6UL_PAD_SD1_CMD_USDHC1_CMD 0x17059

MX6UL_PAD_SD1_CLK_USDHC1_CLK 0x10071

MX6UL_PAD_SD1_DATA0_USDHC1_DATA0 0x17059

MX6UL_PAD_SD1_DATA1_USDHC1_DATA1 0x17059

MX6UL_PAD_SD1_DATA2_USDHC1_DATA2 0x17059

MX6UL_PAD_SD1_DATA3_USDHC1_DATA3 0x17059

So, are the values above acorrding to the hardware designing? and shouled I modify them?

Thanks very much.

Re: imx6ul tf card

igorpadykov — Tue, 03 Nov 2020 06:04:06 GMT

>values above acorrding to the hardware designing? and shouled I modify them?

this depends on custom board layout, so you should find correct settings (drive strength) yourself

based on suggestions provided on reference link with similar issue.

Best regards
igor