When Android runs from 'big' SD card slot I see MMC errors in dmesg. This looks like a hardware issue caused by MMC impedance not matched properly (zif ribbon is quite long...), or by a broken card, or by a broken driver...
mmcblk1: error -84 transferring data, sector 378856, nr 8, cmd response 0x900, card status 0xb00
mmcblk1: retrying using single block read
Not sure if I've ever seen it when running android from 'small' MMC card slot.
nazgee
commented
6 years ago
When Android runs from 'big' SD card slot I see MMC errors in dmesg. This looks like a hardware issue caused by MMC impedance not matched properly (zif ribbon is quite long...), or by a broken card, or by a broken driver...
Not sure if I've ever seen it when running android from 'small' MMC card slot.