mmc r/w errors after setting GPIO

[chema]

Hi,

I have a Pine64-LTS with 16GB eMMC, running the Stretch minimal Sopine kernel by Ayufan (https://github.com/ayufan-pine64/linux-build/releases).

I am trying to install a 3G hat in the Pi bus, and need to enable some GPIO pins. I have followed the tutorial that pfeerick wrote in this forum (https://forum.pine64.org/showthread.php?tid=2088).



I am working with GPIOS 6 (230 in Pine) and 21 (75 in Pine). Just need to put them as output with the 1 value. But a few seconds or minutes (less than 10 minutes) afters setting these GPIOS, I lost the capacity to read or write to the disk (the emmc). It happens even when there is not anything connected to the Pi bus.
These are the errors that I can see in the syslog:

Nov 30 20:02:42 sopine kernel: [169456.474748] sunxi-mmc 1c11000.sdmmc: smc 0 p2 err, cmd 18, RD SBE !!

Nov 30 20:02:42 sopine kernel: [169456.481825] sunxi-mmc 1c11000.sdmmc: data error, sending stop command

Nov 30 20:02:42 sopine kernel: [169456.489060] sunxi-mmc 1c11000.sdmmc: reset:host reset and recover finish

Nov 30 20:02:42 sopine kernel: [169456.496550] mmcblk0: timed out sending r/w cmd command, card status 0x900

Nov 30 20:02:42 sopine kernel: [169456.504094] mmcblk0: not retrying timeout

Nov 30 20:02:42 sopine kernel: [169456.508595] end_request: I/O error, dev mmcblk0, sector 1116624

Nov 30 20:02:42 sopine kernel: [169456.515171] end_request: I/O error, dev mmcblk0, sector 1116632


I have tried several combinations (with or without ataching a hat), but it always happens after touching these GPIOs.

Have anyone see before a problem like this?

Thanks!
Regards
Chema