Slow MMC IO with Raspberry CM3+ Module

Mario Lombardo ml at
Wed Nov 3 11:39:44 CET 2021

Dear u-boot list,

I recently compiled (latest: 2021.10) code of uboot as a boot loader for the Compute Module 3+ (Raspberry). Everything works fine except one issue: the IO from the storage is extreme slow. I read about issues in the past related to ext file systems. However the present issue relates to both ext and fat file systems so I assume its cause is different.

This is what I did:

U-Boot>   setenv pio_kernel "recovery/kernel.img"
U-Boot>   setenv pio_initrd "recovery/initrd.img"
U-Boot>   fatload mmc 0:1 ${kernel_addr_r} ${pio_kernel}
5299624 bytes read in 45262 ms (114.3 KiB/s)
U-Boot>   fatload mmc 0:1 ${ramdisk_addr_r} ${pio_initrd}
24239932 bytes read in 206978 ms (114.3 KiB/s)

The configuration of by build is attached.

Is there anyone else experiencing this kind of issues?

Thank you very much.


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