imx8mm mmc block read error

[jiangxh]

Hi,

We are using i.MX8mm custom board with Linux imx_4.19.35_1.1.0. Some boards will have the problem of mmc block read error during cold start.

But after 10 minutes of power-on, these boards can load the system normally after power-on again.

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U-Boot SPL 2019.04-4.19.35-1.1.0+g6cc5af5 (Oct 07 2021 - 14:26:43 +0000)
power_bd71837_init
DDRINFO: start DRAM init
DDRINFO:ddrphy calibration done
DDRINFO: ddrmix config done
Normal Boot
Trying to boot from MMC2
mmc_load_image_raw_sector: mmc block read error
SPL: failed to boot from all boot devices

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Anyone faced this issue?

Thanks in advance,

Regards,

Jiang Xihui

[trongthinh]

I got the same issues, and the watchdog reset the board every 1 min

U-Boot SPL 2022.04-6.4.0-devel+git.7bd2074193e1 (Sep 08 2023 - 01:58:31 +0000)
DDRINFO: start DRAM init
DDRINFO: DRAM rate 3000MTS
DDRINFO:ddrphy calibration done
DDRINFO: ddrmix config done
Normal Boot
WDT: Started watchdog@30280000 with servicing (60s timeout)
Trying to boot from MMC2
mmc_load_image_raw_sector: mmc block read error
SPL: failed to boot from all boot devices
### ERROR ### Please RESET the board ###

Does anyone resolved it? Please share the solutions.

[igorpadykov]

Hi Bryan

>But after 10 minutes of power-on, these boards can load the system normally after power-on again.

probably heating may improve SD signal shape ( it may be noisy due to impedance mismatch/signal reflections) and one can try to adjust SD drive strength using sect.8.2.5.203 Pad Control Register
(IOMUXC_SW_PAD_CTL_PAD_SD2_CLK)  i.MX 8M Mini Applications Processor Reference Manual

Best regards
igor